Energy Efficiency Study in Building Sector...Energy Efficiency Study in Building Sector 18 January 2014 Prepared for Research & Development Division , Department of Renewable Energy,

Energy Efficiency Study in Building Sector 18 January 2014

Prepared for

Research & Development Division , Department of

Renewable Energy, MoEA, Thimphu, Bhutan

and

UNDAF,

United Nations Development Programme

Thimphu, Bhutan

Department of Renewable Energy, Ministry of Economic Affairs, Royal Government of Bhutan

Acknowledgement

PwC wishes to thank the Department of Renewable Energy (DRE), Ministry of Economic Affairs (MoEA), for

initiating United Nations Development Programme (UNDP) funded project "Energy Efficiency Study in

Building Sector" and engaging PwC India to offer consulting services for the same.

We wish to thank Mr. Karma Tshering, Director, Ms. Dawa Zangmo, Chief Engineer, Mr. Chhimi Dorji,

Executive Engineer, Mr. Sherab Jamtsho, Deputy Executive Engineer and the whole staff of Department of

Renewable Energy for their time and extended co-operation to us.

We wish to express appreciation for co-operation extended to us by the different prestigious buildings to

undertake energy audits in their premises.

We also wish to convey special thanks to Bhutan Power Corporation Limited, for their support in providing all

necessary information and energy consumption data for buildings in various Dzongkhags, captured during

questionnaire survey and detailed energy audits.

The support from various other stakeholders has also been commendable. The successful completion of project

would not have been possible without the support of the different stakeholders who participated in the

stakeholder meeting and provided valuable inputs.


Table of contents

1. Project Objective & Approach 9

1.1. Project objective 9

1.2. Approach adopted to develop energy audit reports of buildings 9

1.2.1. Review of EE policies and initiatives undertaken in the building sector 10

1.2.2. Project inception 10

1.2.3. Assessment of buildings for energy audits 10

1.2.4. Designing of data collection framework 12

1.2.5. Stage 1 -Primary questionnaire survey (walk through audits) 13

1.2.6. Stage 2 -Detailed energy audit 14

2. Building Energy Audit 16

2.1. Case study 1- Institutional building at Thimphu 17

2.1.1. Backdrop 17

2.1.2. Energy consumption and data recording 18

2.1.3. Construction practices at the building 18

2.1.4. Connected load of the building 19

2.1.5. Recommendations 20

2.2. Case study 2- Commercial building at Trongsa 21

2.2.1. Backdrop 21

2.2.2. Energy consumption and data recording 22

2.2.3. Construction practices at the building 23

2.2.4. Connected load at the building 23


2.3. Case study 3- Domestic household at Bumthang 26

2.3.1. Backdrop 26

2.3.2. Energy consumption data 26

2.3.3. Construction practices at the households 27

2.3.4. Connected load at urban and rural households 28

2.3.5. Firewood usage at urban and rural households 29


2.4. Summary of the observations of practices 32

2.4.1. Lighting 32

2.4.2. Heating Ventilation & Air Conditioning (HVAC) 32

2.4.3. Air conditioning 32

2.4.4. Space heating (through electric room heaters) 32

2.4.5. Fans 33

2.4.6. Office and other general equipments 33


2.4.7. Firewood usage 33

2.4.8. Construction practices 33

3. Status of Building Regulations in Bhutan – Standards and Bodies 35

4. International review programs on BEECs 37

5. Climate Zones determination for Bhutan 40

6. Construction Practices 42

6.1. Integration of modern construction designs with traditional features 42

6.1.1. Orientation and shape of the building 42

6.2. Building element construction 46

6.2.1. Foundations 46

6.2.2. Walls 46

6.2.3. Rabsel 47

6.2.4. Openings -Doors and windows 49

6.2.5. Kachhen and Zhu 50

6.2.6. Cornices 51

6.2.7. Roof 51

7. Key inputs or the Approach for the EE plan in buildings 53

8. Efficient and Integrated Design Processes 54

9. Green Building and Passive Guidelines 57

9.1. Alternative Building Materials 57

9.2. Orientation 59

9.2.1. Space orientation 59

10. Building Energy Efficiency Code, 68

11. Implementation Framework 74

11.1. Key actions required for implementation 76

11.1.1. Policy development 76

11.1.2. Market assessment 76

12. Policy Instruments - Recommendations 79

12.1. Introduction of Energy Conservation (EC) Act in Bhutan 79

12.2. Launch of Standard & Labeling (S&L) program 80

12.3. Energy Audits for different buildings in Bhutan 81

12.4. Implementation of BEEC (Building Energy Efficiency Code) 81

12.5. Launch of program for efficiency of Bukhari system 82

12.6. Initiate capacity building programs and strengthen ongoing awareness programs 83

12.7. Energy efficiency policy requirements 85


List of Annexures

Annexure Details Annexure A Energy Audit Report - Tashichho Dzong, Thimphu

Annexure B Energy Audit Report - Bhutan Power Corporation, Corporate Head Office, Thimphu

Annexure C Energy Audit Report - Energy Building, Ministry of Economic Affairs, Thimphu

Annexure D Energy Audit Report - Phuentsholing General Hospital, Phuentsholing

Annexure E Energy Audit Report - Hotel Bhutan Residence, Phuentsholing

Annexure F Energy Audit Report - Yangkhil Resort, Trongsa

Annexure G Energy Audit Report - Trongsa General Hospital, Trongsa

Annexure H Energy Audit Report - Urban & Rural Households, Bumthang

Annexure I Energy Audit Report - Hotel Druk Zhongar, Mongar

Annexure J Energy Audit Report - NRDCL , Mongar

Annexure K Energy Audit Report - Urban & Rural Households, Mongar

Annexure L Bhutan Building Energy Efficiency Code (BEEC)

Annexure M Stakeholder Presentation

* Each of the above annexure is a detailed report which provides the findings obtained in this project. These

annexure are attached separately with this document.

List of Tables

Table 1: Details of questionnaire survey undertaken in Bhutan ............................................................................... 13 Table 2: Details of detailed energy audit undertaken in Bhutan .............................................................................. 14 Table 3 : Measurement and recordings undertaken during detailed energy audit ................................................. 15 Table 4: Building details for energy audit .................................................................................................................. 16 Table 5: General building details I ............................................................................................................................. 17 Table 6: General building details II ............................................................................................................................ 17 Table 7: Energy Performance Index: Institutional building from 2010-11 to 2012-13 ............................................ 18 Table 8: Construction Practices: Institutional building ............................................................................................ 18 Table 9: Electricity consuming sections at building .................................................................................................. 19 Table 10: Recommendations for Institutional building ........................................................................................... 20 Table 11: General building details I- Commercial building ....................................................................................... 21 Table 12: General building details II - Commercial building ................................................................................... 22 Table 13: Energy Performance Index: Commercial building from 2011-12 to 2012-13 .......................................... 22 Table 14: Construction Practices: Institutional building ......................................................................................... 23 Table 15: Electricity consuming sections at commercial building ........................................................................... 24 Table 16: Recommendations for the commercial building ...................................................................................... 25 Table 17: Domestic household details ....................................................................................................................... 26 Table 18: Energy consumption details: Urban and Rural households .................................................................... 27 Table 19: Details of different household building envelope ..................................................................................... 27 Table 20: Details of firewood consumption at households ...................................................................................... 29 Table 21: Recommendations for domestic households ............................................................................................ 30 Table 22: International review of different building energy efficiency programs .................................................. 37 Table 23: Bhutan specific Köppen-Geiger climate classification .............................................................................. 41 Table 24: Different building materials and their attributes - Examples from Bhutan ........................................... 42 Table 25: General guidelines for foundation dimensions in Bhutan ....................................................................... 46 Table 26: Key performance indicators for fenestration ............................................................................................ 71 Table 27: Key performance indicators for HVAC ...................................................................................................... 71 Table 28: Key performance indicators for lighting ................................................................................................... 72 Table 29: Flowchart for different stages of building energy efficiency code for Bhutan ........................................ 74 Table 30: Ranking of policy options for standards and labeling of appliances ....................................................... 81


List of Figures

Figure 1: Project objective ............................................................................................................................................ 9 Figure 2: Project approach ........................................................................................................................................... 9 Figure 3: Bhutan building sector percentage electricity consumption share for 2011 ............................................ 11 Figure 4: Climate zone map of Bhutan ....................................................................................................................... 11 Figure 5: Region wise electricity consumption in buildings in Bhutan in 2011 ....................................................... 12 Figure 6: Regions covered during questionnaire survey ........................................................................................... 13 Figure 7: Building types captured during questionnaire survey ............................................................................... 13 Figure 8 : Regions covered during detailed energy audit .......................................................................................... 14 Figure 9: Building types captured during energy audit ............................................................................................. 14 Figure 10:Active power and electricity consumption profile of Institutional building ........................................... 18 Figure 11:Percentage load distribution at building .................................................................................................... 19 Figure 12: Commercial building - resort at Trongsa ................................................................................................. 21 Figure 13:Active power and electricity consumption profile of commercial building ............................................ 22 Figure 14: Percentage load distribution at commercial building ............................................................................. 23 Figure 15:Percentage load distribution at urban and rural households .................................................................. 28 Figure 16: Traditional bukhari system ...................................................................................................................... 29 Figure 17: Climate zone for Bhutan : Geographic regions overlaid on the administrative regions of Bhutan ...... 40 Figure 18: Traditional building in Bhutan (depicting a rabsel on the side of the wind direction) ........................ 42 Figure 19 : Tapering walls at Bhutan ......................................................................................................................... 47 Figure 20 : Rabsel in walls ......................................................................................................................................... 47 Figure 21 : Types of rabsels used in walls in Bhutan ................................................................................................ 49 Figure 22 : Traditional windows in Bhutan .............................................................................................................. 49 Figure 23 : Traditional windows in Bhutan .............................................................................................................. 50 Figure 24 : Kachhen and zhu timber columns for load bearing in ceilings ............................................................. 50 Figure 25 : Cornices in the walls ................................................................................................................................. 51 Figure 26 : Types of roofs in Bhutan ......................................................................................................................... 52 Figure 27: Different stakeholder involved in building design.................................................................................. 54 Figure 28: Passive/ bio-climate design strategies ..................................................................................................... 57 Figure 29: Ground Insulation .................................................................................................................................... 60 Figure 30: Plinth protection provided by sloping paving for drainage channel ...................................................... 61 Figure 31: Snapshot of a 40 cm gable wall compound insulation system and a porous ceramics brick ............... 62 Figure 32: An inclined roof with insulation with respect to the rafters and highly insulated concrete roof

construction ................................................................................................................................................................ 62 Figure 33: Snapshot for thermal mass in a building ................................................................................................ 63 Figure 34 : Pictorial representation of radiation of heat during day and night ...................................................... 63 Figure 35: Construction from rammed earth ............................................................................................................ 64 Figure 36: Pictorial representation of working of Trombe wall ............................................................................... 65 Figure 37: Working of Trombe wall in respect to day and night ............................................................................. 66 Figure 38: Trombe wall vs. sun space ....................................................................................................................... 66 Figure 39: Types of ventilation that can be implemented in Bhutan ...................................................................... 67 Figure 40: Sealing tape for plaster for air tightness ................................................................................................. 67 Figure 41: Methodology for building energy code compliance ................................................................................ 68 Figure 42: Steps for implementation, enforcement and stability of code ................................................................ 77


List of Abbreviations and Acronyms

MoEA Ministry of Economic Affairs

DRE Department of Renewable Energy

UNDP United Nations Development Programme

BPC Bhutan Power Corporation

ADB Asian Development Bank

DES Department of Engineering Services

MoWHS Ministry of Works and Human Settlements

HVAC Heating Ventilation and Air Conditioning

UPS Uninterrupted Power Supply

LPG Liquefied Petroleum Gas

kW Kilowatt

EPI Energy Performance Index

kWh Kilowatt-hour

BEE Bureau of Energy Efficiency

FTL Fluorescent Tube Light

LED Light Emitting Diode

A.C. Air Conditioning

EER Energy Efficiency Ratio

COP Coefficient of Performance

CFL Compact Fluorescent Lamp

IRR Internal Rate of Return

GHG Green House Gas

CRT Cathode Ray Tube

LCD Liquid Crystal Display

ECM Energy Conservation Measure

S&L Standard & Labeling

BEEC Building Energy Efficiency Code

NSB National Statistics Bureau

BSB Bhutan Standards Bureau

BSQC Bureau of Standards and Quality Control

BMS Building Management System

BBR Bhutan Building Rules - 2002

IS Indian Standards

PWD Public Works Department

ASHRAE American Society of Heating Refrigeration and Air Conditioning Engineers

ASTM American Society for Testing and Materials

ISO International Organization for Standardization

EE Energy Efficiency

LCCA Life Cycle Cost Analysis

CSEB Compressed Stabilized Earth Block

HI Hollow Interlocking

ECBC Energy Conservation Building Code

EPS Expanded Polystyrene

XPS Extruded Polystyrene

PUF Polyurethane Foam


KPI Key Performance Indicators

SHGC Solar Heat Gain Coefficient

U Value Heat Transfer Coefficient

VLT Visible Light Transmission

RCC Reinforced Concrete Cement

AAC Autoclaved Aerated Concrete

BTU British Thermal Unit

CRI Color Rendering Index

CCT Correlated Color Temperature

PMU Project Management Unit

LPD Lighting Power Density

EC Energy Conservation

US EPA United States - Environmental Protection Agency

Nu Ngultrum (BTN)


Energy Efficiency Study in Building Sector

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1. Project Objective & Approach

1.1. Project objective

The project "Development of Energy Codes and Standards for Buildings in Bhutan" aimed at following

three objectives as presented in the Figure 1

Figure 1: Project objective

The tasks outlined above are interdependent on each other. Keeping in view the project objectives , as

standard approach was followed to achieve the proposed outcomes. The outputs from each task were

input in designing the requirements of the next task.

1.2. Approach adopted to develop energy audit reports of buildings

The approach followed for the project is presented in Figure 2.

Figure 2: Project approach

Evaluate the Building Sector and Prepare Detailed Energy Audit Reports

Develop Energy Codes and Standards for Buildings

Recommend Policy Instruments

Review of EE Policies and Initiatives

Undertaken in the Building Sector

Inception Meeting /Assessment of Stakeholders

Assessment of Buildings for Energy

Audits

Designing of Data Collection

Framework

Questionnaire Survey (Walk

through Audit)

Detailed Energy Audits and Energy

Audit Reports



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1.2.1. Review of EE policies and initiatives undertaken in the building sector

Extensive research activity was undertaken to collect the information on the current scenario with

respect to policies and initiatives which drive energy efficiency in the building sector in Bhutan. List of

few important documents reviewed is presented below :

Energy Efficiency Technical Report Bhutan - ADB 2012

Bhutan Energy Efficiency Baseline Study - DRE and UNDP

Bhutan Energy Sector - ADB Evaluation Study

Bhutan Green Building Guidelines Draft - DES, MWHS

Bhutan National Urbanization Strategy, Ministry of Works & Human Settlement - 2008

Bhutan Power Corporation Limited, Tariff Review report - October 2013

Rules of Income Tax Act of the Kingdom of Bhutan, 2001

Key information extracted from these documents include the following aspects related to Bhutan .

Policy and regulatory mechanism in place

Energy baseline scenario in Bhutan

Financial instruments in place

Power scenario and tariff structure

Consumer profile and end usage pattern

Building structure and energy consumption profile

1.2.2. Project inception

An inception meeting with the DRE, was organized on 11th September 2013 to kick-off the project and

discuss the proposed approach. The outcomes of the meeting are outlined below:

The DRE agreed to facilitate/help with the authority letter/support letter for undertaking

audits in different buildings across Bhutan.

A draft data collection framework was agreed with the DRE.

Agreed to undertake the audits in two stages. First stage involve primary questionnaire survey

(walk through) of buildings across Bhutan.

The second stage involves detailed energy of few buildings covering all important regions of

Bhutan.

The DRE agreed to support in facilitating connect with different stakeholders in Bhutan.

1.2.3. Assessment of buildings for energy audits

It was established from the previous studies conducted by the DRE, that the building sector in Bhutan

consumes around 16% of the total energy (including electrical and thermal). The building sector in

Bhutan nearly accounted for 250 GWh of electricity consumption in the year 2011. To carry out the

assessment, the building sector in Bhutan was broadly classified into the following:

Domestic households (urban & rural)

Commercial establishments

Institutional buildings



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Figure 3: Bhutan building sector percentage electricity consumption share for 20111

After the electricity consumption break up in the building sector was established, region-wise

electricity consumption profiles for buildings were drawn up to assess the major electricity consuming

regions in Bhutan . To understand the region and climate zones of Bhutan, the Bhutan map and

different climatic zones were studied to plan the coverage of study. The climatic zone map of Bhutan

is presented at Figure 4.

Figure 4: Climate zone map of Bhutan

For the analysis of building performance, it is important to classify the buildings and their existence in

different climatic zones. The climatic conditions impact the energy consumption in a building. As

presented above, Bhutan climatic zone comprises three zones i.e. Alpine, Mid Montana and Sub

Tropical.

1 Bhutan Energy Efficiency Baseline Study, Dec 2012, DRE

Urban Households

38%

Rural Households

26%

Institutional buildings

19%

Commercial Establishment

17%

Percentage electricity consumption in 2011



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From previous studies conducted by the DRE, it was established that, buildings in the western region

of Bhutan consumes close to 62% of the total electricity in buildings in Bhutan. Thimphu, Chhukha

and Paro are the dominant electricity consuming dzongkhags in western region . The break- up of

electricity consuming areas and their distribution is presented at Figure 5.

Figure 5: Region wise electricity consumption in buildings in Bhutan in 20112

To develop an assessment plan for buildings, the following criteria were used to select buildings.

Type of buildings ( domestic, institutional and commercial)

Climatic zone ( alpine, mid-montana and sub-tropical)

Region ( eastern, central and western)

Energy consumption pattern

As evident from Figure 4 and Figure 5, most of the criteria's were covered with the help of energy

audits of buildings falling in Thimpu, Paro and Chhukha as they cover all the climatic zones and have

substantial share in the total energy consumption in Bhutan. But for the overall status of buildings in

different regions of Bhutan and also to cover rural households, a sample was developed to cover all the

important regions.

1.2.4. Designing of data collection framework

After assessing the selection criteria of buildings for energy audits in Bhutan, a data collection

framework was designed and shared with the DRE. The data collection framework captured the

following areas:

1. Total energy load of the building and built up area

2. Energy consumption/end use consumption (electrical & thermal)

Lighting

HVAC

Heating systems (space heating)

Water heating system

Ceiling fans

Others

2 Bhutan Energy Efficiency Baseline Study, Dec 2012, DRE

Thimphu 41%

Chhukha 12%

Paro 9%

Gelephu 5%

Punakha 5%

Samste 3%

Others 25%

Percentage Electricity Consumption in 2011



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3. Building envelope and construction practices( for input to building code)

Wall/roof/ceiling

Windows and doors

Fenestration

Insulation

Traditional construction practices

1.2.5. Stage 1 -Primary questionnaire survey (walk through audits)

An initial questionnaire survey (walk through audits) was undertaken to analyze the building to be

considered for detailed energy audits. The questionnaire survey captured all the zones and regions of

Bhutan. The break- up of sample of buildings covered in different building type categories and their

regional break up provided in the Table 1.

Table 1: Details of questionnaire survey undertaken in Bhutan

Dzongkhags/ Building types

Institutional

buildings

Commercial establishments

Urban domestic

Rural domestic

Total

Thimphu 13 13 6 6 38

Chhukha 5 5 5 3 18

Paro 5 5 4 3 17

Samtse 2 2 2 2 8

Wangdi 2 2 2 2 8

Trongsa 2 2 2 2 8

Bumthang 2 2 2 2 8

Mongar 2 2 2 2 8

Total 33 33 25 22 113

Figure 6: Regions covered during questionnaire survey

Figure 7: Building types captured during questionnaire survey

It can be seen from Table 1 and

Figure 6 that questionnaire survey captured all the zones, regions and building types for the

assessment. The following outcomes were achieved through walk through audits:

29%

29%

22%

20%

Building types for questionnaire survey

Institutional Buildings

Commercial Establishments

Urban Domestic

Rural Domestic



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Overall energy consumption of different building types was established

Total building area of buildings

Availability of detailed end use consumption data and the electricity bills of the last few years

All the information gathered through walk through audits were useful to shortlist buildings for

detailed energy audits.

1.2.6. Stage 2 -Detailed energy audit

Sample buildings for detailed energy audits were finalized from questionnaire survey of the building

sample considering following different parameters:

Energy consumption pattern of the buildings surveyed

Different loads observed during walk through

Construction practices

Regions and zones in Bhutan

Availability of data and willingness of building owners

The details of buildings and regions captured during detailed energy audit are provided at Table 2.

Table 2: Details of detailed energy audit undertaken in Bhutan

S.No Building

types

Thimphu Chhukha Trongsa Bumthang Mongar Total

1 Institutional

buildings

4 1 1 - 1 7

2 Commercial

establishments

- 1 1 1 1 4

3 Urban domestic 1 - - 2 2 5

4 Rural domestic - - - 2 2 4

Total 5 2 2 5 6 20

Figure 8 : Regions covered during detailed energy audit

Figure 9: Building types captured during

energy audit

It can be seen from Table 2 and Figure 8 that energy audit captured all the zones, regions and building

types for the assessment. The components undertaken in the detailed energy audit are presented at

Table 3

35%

20% 25%

20%

Building for detailed energy audit

Institutional Buildings

Commercial Establishments

Urban Domestic

Rural Domestic



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Table 3 : Measurement and recordings undertaken during detailed energy audit

S.No Areas of energy audit Assessment of areas of energy audit

Mode of assessment

1 Electrical recording (24 hour data was recorded )

Energy consumption Krykard three phase meter

Active power consumption Krykard three phase meter

Apparent power consumption Krykard three phase meter

Power factor Krykard three phase meter

Frequency Krykard three phase meter

2 Lighting

Lux levels Testo lux meter

Lighting points assessment Audit observation

Types of lighting and consumption, fixtures

Audit observation

3 HVAC Humidity & Temperature Testo Hygrometer

Rated values of heating and cooling equipments

Audit observation

4 Room heaters Power consumption in room heaters Krykard single phase meter

Humidity and temperature Testo hygrometer

5 Ceiling fans Power consumption Krykard single phase meter

6 Water heating system Rated values Audit observation

7 General office equipments

Rated values Audit observation

8 Kitchen/laundry/special equipments

Rated values Audit observation

9 Building envelope

Wall/ roof / ceiling Discussion and audit observation

Windows and doors Measurement, discussion and Audit observation

Fenestration Discussion and audit observation

Insulation Discussion and audit observation

Traditional construction practices Discussion and audit observation

10 Bukhari system

Firewood consumption Discussion and audit observation

Space heating Discussion and audit observation

Outlines of energy audits are discussed in the next chapter.



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2. Building Energy Audit

The detailed energy audit was useful to assess the energy consumption profile in buildings and types

in different regions/zones. Building audits also helped assess end -use energy consumption in

buildings and the efficiency of different energy consuming equipments and appliances.

As discussed in the previous section, a total of 20 buildings were considered for detailed energy audits.

The details of buildings considered for energy audits are presented at Table 4:

Table 4: Building details for energy audit

Buildings (Coded)

Region Building type

Climatic zone

Built up area (Sq. m)

Annual energy consumption (2012-13) (kWh/year)

Energy Performance Index (2012-13) (kWh/Sq.m/year)

Building 1 Thimphu, western Bhutan

Institutional Mid-montana

6605 314010 47.54



4380 309420 70.64



680 62000 91.18


Institutional Alpine and Mid-montana

5172.16 383200 74.09


Domestic urban

Mid-montana

278.7 31531 113.14

Building 6 Phuentsholing, south -western Bhutan

Institutional Sub-tropical 6320 257847 40.80

Building 7 Phuentsholing, south -western Bhutan

Commercial Sub-tropical 976 74960 76.80

Building 8 Trongsa, central Bhutan

Commercial Mid-montana

1586.3 184860 116.5

Building 9 Trongsa, central Bhutan


2048.5 60900 29.7

Building 10

Bumthang, central Bhutan

Commercial Alpine and Mid-montana

5785 303161 52.19

Building 11


Domestic urban

Alpine and Mid-montana

93.5 859 9.19

Building 12


Domestic urban


106.3 1648 15.50

Building 13


Domestic rural


83.1 449 5.40

Building 14

Bumthang, Central Bhutan

Domestic rural


83.2 3389 40.73

Building 15

Mongar, eastern Bhutan

Commercial Mid-montana

1152.6 38240 33.2

Building 16



662.3 28287 42.7

Building 17


Domestic urban

Mid-montana

51.5 1258 24.43



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Building 18


Domestic urban

Mid-montana

51.5 696 13.51

Building 19


Domestic rural

Mid-montana

84.9 1849 21.78

Building 20


Domestic rural

Mid-montana

55.3 904 16.35

Intentionally, the names of the buildings are not shared in the report. The purpose is to understand

the practices in different building types in Bhutan.

As such detailed energy audits reports of some of the important buildings have been prepared and

attached in Annexure, and audit results of some building types have been discussed as case studies.

The detailed energy audit report of some important buildings are provided from Annexure A to

Annexure K. Following building types is discussed in next section as case study for this report.

Institutional building at Thimphu

Commercial building at Trongsa

Domestic household at Bumthang

2.1. Case study 1- Institutional building at Thimphu

The components of energy audit captured are discussed next in brief:

2.1.1. Backdrop

Table 5: General building details I

Sr. no Particulars Details

1 Date of energy audit 21 October 2013

2 Climatic zone Mid- montana

3 Building type Institutional

4 Year of operation November 2009

5 Total complex area (sq m) 10617

6 Total built-up area (sq m) 4380

7 Source of energy Electricity

8 Any other energy source Battery bank, UPS for the server room and LPG for cooking

9 Office operating days Monday to Friday

10 Office operating hours 9 am to 5:30 pm

11 Sanctioned load 384 kW

12 Consumer no 100000667 and 100000678

The building complex had three buildings in its complex under the same meter. The details of the individual building are provided at Table 6.

Table 6: General building details II

Buildings Built up area No of storied

Main building 3356 sq. m Basement + G +4+ Jamtho

Annex I 409 sq. m G+1

Annex II 614 sq. m Basement + G + 1. It has kitchen & canteen in the basement



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2.1.2. Energy consumption and data recording

Energy consumption data for the past three years was extracted from Bhutan Power Corporation

(BPC) to assess the actual Energy Performance Index(EPI) of the building as presented in Table 7.

Table 7: Energy Performance Index: Institutional building from 2010-11 to 2012-13

Parameters 2010-11 2011-12 2012-13

Units consumed (kWh/year) 212640 308400 309420

Built-up area (sq.m) 4380 4380 4380

EPI index (kWh/sq.m/year) 48.55 70.41 70.64

Electrical load profiling was recorded for 24 hours using the krykard three phase power analyzer. The

total building load during the day of recording and total electricity consumption are presented in

Figure 10.

Figure 10:Active power and electricity consumption profile of Institutional building

Total electricity consumption (kWh) of the building measured during 24 hours is

2,045 kWh.

2.1.3. Construction practices at the building

The energy audit included capturing construction practices as well as components of the building envelope (exterior shell).The components of a building envelope include exterior walls, foundation, and the roof. Energy use within the building is dependent on materials used and construction practices adopted. The details of construction material used at the building are presented at Table 8.

Table 8: Construction Practices: Institutional building

Parameters Material Insulation Age ( Years) Condition U -value (W/m2K)

Walls Solid brick wall (brick

228 mm, plaster)

No 4 Good Approx 2.11

0 20 40 60 80

100 120 140 160

9:2

0:0

0 A

M

11:0

0:0

0 A

M

12:4

0:0

0 P

M

2:2

0:0

0 P

M

4:0

0:0

0 P

M

5:4

0:0

0 P

M

7:2

0:0

0 P

M

9:0

0:0

0 P

M

10:4

0:0

0 P

M

12:2

0:0

0 A

M

2:0

0:0

0 A

M

3:4

0:0

0 A

M

5:2

0:0

0 A

M

7:0

0:0

0 A

M

8:4

0:0

0 A

M

Active power profile - kW

kW

0

500

1000

1500

2000

2500

9:2

0:0

0 A

M

11:1

0:0

0 A

M

1:0

0:0

0 P

M

2:5

0:0

0 P

M

4:4

0:0

0 P

M

6:3

0:0

0 P

M

8:2

0:0

0 P

M

10:1

0:0

0 P

M

12:0

0:0

0 A

M

1:5

0:0

0 A

M

3:4

0:0

0 A

M

5:3

0:0

0 A

M

7:2

0:0

0 A

M

9:1

0:0

0 A

M

Electricity consumption profile - kWh

kWh



PwC 19

Ceiling Reinforced cement

concrete (concrete cast

dense reinforced)

No 4 Good Bet. 2.5 - 3.0

Roof GI sheets/wooden truss

(no insulation)

No 4 Good Bet. 0.9 to 1

Building fenestration was also captured during the audit. Following are the highlights:

Newly constructed window and good capacity to capture daylight

All single pane glass have an aluminium frame

All windows are provided with curtains

The main building has a glass wall at the front

2.1.4. Connected load of the building

Connected load of the building was captured during the energy audit to assess the percentage of

different energy consuming loads installed at the building. The list of different electricity consuming

sections and their percentage load distribution are

provided at Table 9 and Figure 11.

Table 9: Electricity consuming sections at building

Sr. no

Electricity consuming sections

Total load (kW)

1 HVAC 626.37

2 Office equipments 71.86

3 Only heating (room heaters)

48

4 Lighting 30.024

5 Kitchen & lift load 12.79

Total 789

Figure 11:Percentage load distribution at building

Important observations from energy audit are provided below:

HVAC is the major load with 79% share.3

Split air conditioners are used only at the data centre and control room for process requirement and not for comfort. ACs installed are either no star or BEE’s 2 star labeled.

55% of the total lighting load is covered by T12.

Radiator type heaters were used which consumes nearly 20% more power than the rated value.

It can be established that, lightings and air conditioners installed are not that efficient. Introduction of energy efficient lightings & air conditioners can significantly reduce the energy consumption at the premises. Therefore recommendations were suggested and cost benefit analysis of different options were done to identify most cost effective options.

3 During the study, the HVAC load was not operational as there was no heating requirements.

79%

9% 6% 4% 2%

Load distribution at the building

HVAC

Office Equipments

Only Heating (Room Heaters)

Lighting

Kitchen & Lift Load



PwC 20

2.1.5. Recommendations Table 10: Recommendations for Institutional building

Sr. no

Suggested measure Annual energy saved (kWh/year)

Annual monetary savings ( Nu/year)

Anticipated investment (Nu)

Simple payback period (months)

Discounted payback (months)

Internal rate of return

GHG reduction (tonne of CO2/year) (Considering saved energy is exported to India)

Lighting

1 Use of electronic chokes with inherent losses of 1 W instead of the copper chokes with inherent losses of 14 W(magnetic) in all T12 FTLs (40W)

9,195 19,769 56,910 35 50 (Less than equipment life)

25.17 7.82

2 Replacement of T12 FTLs (40W) that have magnetic ballast with energy efficient T5 FTLs (28 W) that have electronic ballast

18,390 39,539 1,13,820 35 50 (more than equipment life)

16.31 15.63

3 Replacement of T12 FTLs (40W) that have magnetic ballast with the latest LED based tube lights (18W)

25,463 54,745 5,69,100 125 More than equipment life

4.74 (Not feasible)

21.64

AC

1 Replacement of 2 ton 1 star split AC (EER - 2.62 ) with 2 ton 5 star split AC (EER - 3.31)

53,668 1,15,386 5,48,625 57 88 (more than equipment life)

11.76 45.62

2 Replacement of 1.5 ton 1 star split AC (EER - 2.6 ) with 1.5 ton 5 star split AC (EER - 3.31)

30,065 64,640 3,27,600 61 99 (more than equipment life)

11.65 25.56

3 Replacement of 2 ton 1 star split AC (EER - 2.62 ) with 2 ton 3 star split AC (EER - 2.91)


Not feasible 21.81

4 Replacement of 1.5 ton 1 star split AC (EER - 2.6 ) with 1.5 ton 3 star split AC (EER - 2.91)


Not feasible 12.69

From all the options discussed above, option 1 and 2 in lighting gives best replacement rationale having positive IRR. As the electricity cost in Bhutan is very less compared to other developing or developed countries, these options don't reflect very attractive payback in monetary terms but their energy consumption reduction potential remains very high.



PwC 21

2.2. Case study 2- Commercial building at Trongsa

Snapshot of commercial building is provided at Figure 12. The components of energy audit captured at

commercial building are discussed next in brief:

Figure 12: Commercial building - resort at Trongsa

2.2.1. Backdrop

Table 11: General building details I- Commercial building

S. No. Particulars Details

1 Date of energy audit 21st November 2013

2 Building type Commercial building - Resort

3 Year of establishment 2007

4 Total built-up area 1586.3 m2

5 Contact person Mr. Kamal (Manager), Contact no. 975 17745930

6 Primary source of energy at building

Electricity

7 Climatic zone Mid- montana

8 Other sources of energy Wood for space heating at restaurant only and LPG for cooking food

9 Operating hours

The facility remains open throughout the year (24 hours, 365 days). However, the electrical load will not be full for the entire year and will vary as per the usage. Thus, based on discussion with resort staff, the average actual working hours (for electricity usage) per day has been considered as 14 hours.



PwC 22

10 Sanctioned load 100 kW

11 Consumer No. 60000370

The commercial building is a resort at Trongsa. The facility has total 21 rooms for guests categorized into two different types, standard room and deluxe room. The complete bifurcation of different sections in the facility is provided at Table 12.

Table 12: General building details II - Commercial building

S. No. Different sections at the facility premises No. of rooms of each type

1 Standard room 20

2 Deluxe room 1

3 Kitchen 1

4 Restaurant 1

5 Reception lobby 1

6 Laundry 1

7 Conference hall 1

2.2.2. Energy consumption and data recording

Energy consumption data for the past two years was extracted from BPC to assess the actual EPI of

the building as presented in Table 13.

Table 13: Energy Performance Index: Commercial building from 2011-12 to 2012-13

Parameters 2011-12 2012-13

Units consumed (kWh/year) 1999 1999

Builtup area (Sq.m) 1586.3 1586.3

EPI Index (kWh/Sq.m/year) 117.3 116.5

Electrical load profiling was recorded for 24 hours using krykard three phase power analyzer. The

total load during the day of recording and total electricity consumption is presented in Figure 13.

Figure 13:Active power and electricity consumption profile of commercial building

0

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70

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Active power profile (kW)

Kilowatts

0

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1200

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Electricity consumption profile (kWh)

kWh



PwC 23

Total electricity consumption (kWh) of the building measured during 24 hours is

1,008 kWh.

2.2.3. Construction practices at the building

The energy audit included capturing construction practices as well as components of the building envelope (exterior shell).The components of a building envelope include the exterior walls, foundation, and the roof. Energy used within the building is dependent on the materials used and the construction practices adopted. The details of construction material used at the building are presented at Table 14.

Table 14: Construction Practices: Institutional building

Parameters Material Insulation Age Condition U Value

(W/m2K)

Exterior

walls

(Reception &

restaurant)

Solid brick (305 mm,

plaster)

No 6 Good 1.64 to 2.11

Inner walls

(Reception &

restaurant)

Wooden No 6 Good 0.28 to 0.6

Room walls Combination of wood

boards, glass wool and

plaster

Yes 6 Good 0.82

Ceiling Combination of wood

boards, glass wool and

plaster

Yes 6 Good 2.92

Roof GI sheets / wooden

truss

No 6 Good 0.9 to 1

Building fenestration was also captured during the audit. Highlights of the fenestration are as follows:

Fenestration at the building is six years old

The building has all single pane glass with either an aluminium or wooden frame

All window's were provided with black films and curtains

2.2.4. Connected load at the building Connected load of the building was captured

during the energy audit to assess the percentage

of different energy consuming loads installed at

the building. The list of different electricity

consuming sections and their percentage load

distribution are provided at Figure 14 and Table

15.

Figure 14: Percentage load distribution at commercial building

7% 2%

35%

40%

16%

Electrical load distribution (kW)

Lighting

Fans

Heating

Office & other general equipments

Kitchen & laundry equipments



PwC 24

Table 15: Electricity consuming sections at commercial building

S. No. Electricity consuming sections Total Load (kW)

1 Office & other general equipments 50.3

2 Only heating (room heaters) 44

3 Lighting 9.417

4 Kitchen & laundry 19.59

5 Fans 2.76

Total 126.067

Some observations of the energy audit of the building are provided below:

Geyser is the major load under office and general equipment category with a 40% share. None of the geysers were star rated.

Room heaters used were of radiator type and were the second major load with 35% share. They consumed 25% more power than the rated value.

Among the lighting load nearly 69% comprised of Incandescent and T-12.

Ceiling fans used at resort were rated for 70 W.

It can be thus established that, lightings and fans installed are not that efficient. Introduction of energy efficient lightings and fans can significantly reduce the energy consumption at the premises. Therefore recommendations were suggested and cost benefit analysis of different options was done to identify most cost effective options.



PwC 25

2.2.5. Recommendations Table 16: Recommendations for the commercial building

Energy conservation measure (ECM)

Existing

connecte

d load

(kW)

Reduced

connected

load (kW) post

ECM

implementatio

n

Energy

savings

(kWh/year

)

Annua

l GHG

saving

s

(tones)

Investmen

t required

(Nu)

Simple

payback

(months

)

Discounte

d payback

(DPB)

(months)

IRR

Categor

y based

on DPB

Priorit

y

Replacing incandescent bulbs (25 W) with LEDs (3W)

3.75 0.45 16863 14.33 47250 15.6 23.5 59.7 % Medium term

Medium

Replacing incandescent bulbs (25 W) with CFLs (5W)

3.75 0.75 15330 13.03 14175 5.2 8 63.6 % Short term

High

Replacing T12 tube lights having magnetic ballast (54 W) with LED based tube lights (18 W)

2.7 0.9 9198 7.81 105000 64 Not feasible 11 % Long term

Low

Replacing T12 tube lights having magnetic ballast (54 W) with T5 having electronic ballast (28 W)

2.7 1.4 6643 5.64 21000 17.6 More than the life of equipment

6.33 % Medium term

Medium

Replacing magnetic type ballasts in FTLs (14 W) with electronic type (1 W)

0.7 0.05 3321 1.52 10500 17.6 26.6 27.7 % Medium term

Medium

Replacing 70 W ceiling fan with energy efficient 50 W fan

1.61 1.15 966 0.82 41055 237 More than equipment life

Not feasible

Long term

Low

From all the options discussed above, option 1, 2 and 5 in lighting gives best replacement rationale having positive IRR. As the

electricity cost in Bhutan is very less as compared to other developing or developed countries, these options do not reflect very

attractive in terms of monetary payback, however their energy consumption reduction potential remains very high.



PwC 26

2.3. Case study 3- Domestic household at Bumthang

The components of energy audit captured at domestic - urban and rural households are discussed next

in brief:

2.3.1. Backdrop

Table 17: Domestic household details

Details

Urban house – U1

Owner name: Mr. Kinley Tenzin

Contact No.: 975 77383402

Built-up area: 93.5 meter2

Building sections: 3 bedroom, 1 living

room, 1 kitchen and 2 toilets

Year of establishment: 2003

Primary source of energy: Electricity

Other source of energy: Wood for space

heating and LPG for cooking food

Sanctioned load: 20 kW

Consumer (CA No.): 30043995

Meter No.: 374 (single phase)

Urban house – U2

Owner name: Mr. Phuntsho

Contact No.: 975 17689875


Building sections: 2 bedroom, 1 living

room, 1 prayer room, 1 kitchen and 1 toilet








Details

Rural house – R1

Owner name: Mr. Thinley (Ugyen

Lhadon)

Contact No.: 975 17748298


Building sections: 2 bedroom, 1 kitchen

and 1 toilet








Rural house – R2

Owner name: Mr. Lodey

Contact No.: 975 17593129


Building sections: 2 bedroom, 1 kitchen

and 1 toilet








2.3.2. Energy consumption data

Energy consumption data for past two years was extracted from BPC Dzongkhag office at Bumthang.

The energy consumption details of urban and rural homes are presented in Table 18.



PwC 27

Table 18: Energy consumption details: Urban and Rural households

Urban 1 Urban 2

Parameters 2011-12 2012-13 2011-12 2012-13

Units consumed (kWh/year) 779 859 2901 1648

Builtup area (Sq.m) 93.5 93.5 106.3 106.3

Rural 1 Rural 2

Parameters 2011-12 2012-13 2011-12 2012-13

Units consumed (kWh/year) NA 449 1643 3389

Builtup area (Sq.m) 83.1 83.1 83.2 83.2

2.3.3. Construction practices at the households

The energy audit included capturing construction practices as well as components of the household

envelope (exterior shell).The components of a envelope include the exterior walls, foundation, and the

roof. Energy use is dependent on the materials used and the construction practices adopted. The

details of construction material used are presented at Table 19.

Table 19: Details of different household building envelope

Household Parameters Material Additional

insulation

material

Condition U Value

(W/m2K)

U1 Exterior walls Ekra wall (cement & timber

mat combination)

No Good Approx 2.11

Inner walls Wooden wall No Good 0.28 to 0.6

Ceiling Combination of wood and

mud/cement

No Good 0.3 to 0.7

Roof GI sheets/wooden truss (No

Insulation)

No Good 0.9 to 1

U2 Exterior walls Ekra wall (cement and timber mat combination)

No Average Approx 2.11


Ceiling Combination of wood and mud/cement

No Good 0.3 to 0.7

Roof GI sheets/wooden truss (No Insulation)

No Good 0.9 to 1

R1 Exterior walls Brick wall No Average Approx 2.11



No Good 0.3 to 0.7

R2 Exterior walls Ekra wall (cement and timber mat combination)

No Good Approx 2.11

Inner walls Wooden wall 0.28 to 0.6


No Good 0.3 to 0.7

Roof GI sheets/wooden truss (No Insulation)

No Good 0.9 to 1



PwC 28

Fenestration was also captured during the audit. Highlights of the fenestration are as follows:

Fenestration were 10- 15 years old for urban homes and nearly 6 years for rural homes

All the household has single pane glass with a wooden frame

All window's were provided with curtains

2.3.4. Connected load at urban and rural households

Connected load of the urban and rural households were captured during the energy audit to assess the

percentage of different energy consuming loads installed at the building. The percentage load

distribution for urban and rural households is presented at Figure 15.

Figure 15:Percentage load distribution at urban and rural households

Some of the observations of the energy audit are provided below:

Among the lighting load, usage of T12 and incandescent is much higher than CFLs.

Urban households were using geysers and none of the geysers were star rated.

Room heaters were found only in urban households. The heaters were drawing about 25% more power than the rated value.

Every household has television. The usage of conventional CRT televisions is more. The consumption of CRT is much higher than LCD/LED.

5%

39%

27%

29%

Urban house 1 (U1), 12.2 kW

6%

25%

29%

40%

Urban house 2 (U2), 9.42 kW

12% 6%

82%

Rural house 1 (R1), 1.84 kW

6% 5%

89%

Rural house 2 (R2), 2.8 kW

Electrical load distribution (kW)



PwC 29

During the survey, the household occupants were questioned to know their awareness and interest

related to energy efficiency. The occupants had a constructive opinion towards energy efficiency but

they were not fully aware about different ways to save energy. Based on the survey, there is a need to

aware residential consumers towards latest developments & initiatives in the energy efficiency sector.

This will provide an opportunity to consumers for saving energy through different options.

In the years to come, it is expected that the consumption will increase as the occupant’s living

standards and luxury demands go up. With the increase in electricity prices there will have a major

impact on the households. Hence, efficient use of electricity is the need of the hour.

Just because it is rational for consumers to invest in all conservation opportunities with a considerable

payback does not mean that consumers know what those opportunities are. While providing

homeowners with information about what to do is necessary, care must be taken in how that

information is presented. Practical experience shows that presenting too many choices can actually

increase the likelihood that someone won’t choose at all.

Considerable awareness on energy efficiency measures plays an important role in achievement of

desired results. The government of Bhutan and all associated stakeholders shall initiate efforts to enhance the capacity and know-how of local people towards the benefits associated with energy efficiency improvements. It will not only add to uptake of energy conservation but will also make the economy more advanced in terms of availability of material and equipments. Based on the connected load observations it can be established that, introduction of energy efficient lightings can significantly reduce the energy consumption at the households. Therefore calculations were undertaken to assess the energy saving if replacement is considered at the households.

2.3.5. Firewood usage at urban and rural households

Firewood is a common source used for space heating in Bhutan. A bukhari is a traditional space

heater (firewood-burning stove) used in Bhutan Table 20. Snapshot of traditional bukhari system is

presented at Figure 16.

Table 20: Details of firewood consumption at households

Household Annual consumption (tonnes) Annual expenditure (Nu.)

U1 5 5700

U2 5.5 6000

R1 2.5 800

R2 4.5 2050

Figure 16: Traditional bukhari system

2.3.5.1. Key observations

During the energy audit, the composition of flue gases

releasing from the exhaust stack of bukhari was

captured. The excess air levels in the flue gas were on

the higher side which signifies that the overall efficiency

of the system is low. The overall efficiency generally

ranges between 10 to 20 percent only. This is due to the

fact that the stoves generally have lot of heat loss due to

inefficient design & local construction.



PwC 30

2.3.5.2. Energy efficiency opportunities

• To get the most out of firewood, it is important to properly dry (season) the wood.

Well-seasoned firewood will start easily & burn bright with little smoke.

• The conventional stoves (locally made) burn wood inefficiently, which wastes firewood,

pollutes the air and leaving dust particles. Newer stoves can reduce smoke and dust, as

well as cut heating expenses. The Unites States Environment Protection Agency (US EPA)

has initiated certification of wood stoves so as to make it energy efficient and safer for

home usage.

As per the US EPA program there can be approximately 50% more efficient operation

of wood stoves and can limit the use of firewood to one-third for the same heat. DRE is

already undertaking a program for the Bukhari system improvement in Bhutan.

2.3.6. Recommendations

Table 21: Recommendations for domestic households

Household Suggested ECMs measures

Payback period (months)

Type of category

Level of priority

Annual electricity saving (kwh)

Annual GHG emission saving (tonnes)

U1

1. Replacement of T12 tube lights with T5, and,

2. Replacement of incandescent bulbs with CFLs

Combined payback for both ECMs is 24 months.

Separately it is 50 months for ECM1 and 12 months for ECM2.

Medium term

High 706 0.6

3. Replacing incandescent bulbs with LED bulbs

30 Medium term

Medium 518 0.44

Use of thermostat in electric room heaters

27 Medium term

Medium 648 0.55

Replacement of T12 tube lights with LED lights

172 Long-term

Low 394 0.33

U2

1. Replacement of T12 tube lights with T5, and,

2. Replacement of incandescent bulbs with CFLs

Combined payback for both ECMs is 29 months.

Separately it is 44 months for ECM1 and 8 months for ECM2.

Medium term

High 761 0.65

3. Replacing incandescent bulbs with LED bulbs

30 Medium term

Medium 388 0.33

Use of thermostat in electric room heaters

27 Medium term

Medium 325 0.28

Replacement of T12 tube lights with LED lights

157 Long-term

Low 605 0.53

R1

Replacement of incandescent bulbs with CFLs

5 Short-term

High 408 0.34

Replacing incandescent bulbs with LED bulbs

41 Long term

Low 417 0.35

R2 Replacement of incandescent bulbs with

8 Short-term

High 108 0.09



PwC 31

Household Suggested ECMs measures

Payback period (months)

Type of category

Level of priority

Annual electricity saving (kwh)

Annual GHG emission saving (tonnes)

CFLs

Replacing incandescent bulbs with LED bulbs

30 Medium term

Medium 129 0.11

From all the ECMs discussed, the options that give the best replacement rationale have

been highlighted with high priority. Considering the high priority ECMs the energy

consumption of households can be reduced and there will be cost savings in following

manner.

Urban house 1 – 706 electricity units equivalent to Nu 1313 / annum.

Urban house 2 – 761 electricity units equivalent to Nu 1415 / annum.

Rural house 1 – 408 electricity units equivalent to Nu 759 / annum.

Rural house 2 – 108 electricity units equivalent to Nu 200 / annum.



PwC 32

2.4. Summary of the observations of practices

Detailed energy audits of different buildings was very helpful in assessing the end use energy

consumption . The summary of section wise observations and status of energy efficiency

options is presented below:

2.4.1. Lighting

Primarily the lighting load in most buildings comprises of three types of lighting lamps. These

are T12 tube lights having magnetic ballast, incandescent bulbs and compact

fluorescent lamps (CFLs).

In most buildings, majority of the lighting load is through connections of T-12 and

incandescent bulbs. In many buildings the load pertaining to these lamps is higher than 60%

of the total lighting load.

Although CFL and energy efficient T5 tubes are available in the local markets, the usage of T-

12 tube lights and incandescent bulbs is dominant.

During the energy audit, it was established that sufficient daylight was available in most of the

buildings and can be utilized without turning-on any light point. However, it was also

observed that most of the light points were kept in the switched-on mode during the day time.

The electricity consumption can be reduced by merely switching off extra lights as the actual

lux level was far above the recommended levels. This can be achieved through developing

efficient lighting design and initiating energy efficiency awareness plans.

2.4.2. Heating Ventilation & Air Conditioning (HVAC)

As such an integrated HVAC system is not very common in the commercial and institutional

buildings at Bhutan. This can be attributed to the climatic conditions, as the requirement for

heating load is dominant over the cooling requirement.

However, it is expected that with the growth of tourism and other commercial sectors in fast

developing economy like Bhutan the usage/demand for HVAC is set to rise in near future. But

the overall observation is that HVAC (cooling) is not the major load in overall consumption.

The energy conservation building code for buildings in Bhutan can facilitate various practices

and measures that will be helpful in establishment of energy efficient HVAC operation.

2.4.3. Air conditioning

The load pertaining to air conditioners is dominant in regions falling under the sub-tropical

climate zone of Bhutan such as Phuentsholing. The air conditioners used were either BEE’s 2

star or no star rated.

High energy efficient star rated ACs are available in the Bhutanese market and there exists a

significant saving potential if replacement of existing with efficient ones is considered.

2.4.4. Space heating (through electric room heaters)

Electric room heaters (radiator type mostly) hold a significant percentage (around 30%-35%)

in the total connected load of most buildings. The usage of electric heaters was more



PwC 33

prominent in regions falling under the mid-montana and alpine climatic zones (cold

climates).

Moreover, it was observed that these electric heaters consume nearly 20-25% more power

than the rated value. Regulatory control over the quality check of heaters is important to

control excess power consumption.

2.4.5. Fans

Ceiling fan was the major load among the fan categories. Most ceiling fans were rated for 70W

and none of them were star rated. These loads were mostly available in regions falling under

subtropical zone.

2.4.6. Office and other general equipments

Geysers contribute around 60-70% load under the general equipments category in most

buildings. None of the geysers were star rated.

The load pertaining to geysers is quite high and therefore replacement of the existing geysers

with star rated ones has the potential to bring significant energy savings through reduction in

standby losses.

Electric rice cookers having 700 W to 1500 W rated electricity consumption were one of the

most common appliances found in almost every building. The refrigerators are the next most

common appliance found in every facility.

2.4.7. Firewood usage

In addition to room heaters, the households also use firewood based Bukhari system for space

heating. Bukhari is used for burning firewood. It is a kind of wood stove which is most common in

entire Bhutan. The firewood is usually sourced from hardwoods and softwoods. The usage of firewood

is dominant in regions falling under alpine and mid-montana climatic zones such as Bumthang,

Trongsa, Thimpu etc.

On an average an urban household consumes 5 tonnes of firewood in a year and rural

household consumes 2.5 tonnes in a year.

The Bukhari (wood burning stove) were mostly locally made and efficiency of the system

generally remains between 10-20%.

2.4.8. Construction practices

Type of building material, fenestration material and insulation used were captured and it was found

that most of the buildings were without any insulation. The construction practices are discussed in

greater details in next sections. .

T



PwC 34

The need for standardization of construction practices and regulating the measures for

lighting, HVAC, heating system and other energy efficiency practices in the building

encourages the need for development of a set of guidelines or code for efficient use of

energy inside the buildings in Bhutan, without hindering the traditional architecture.

Thus there is a need for energy standards and codes for buildings in Bhutan to

benchmark different energy consuming practices being followed.

The field observations chapters. obtained in this study has been used for development

of Bhutan energy efficiency code (BEEC). The process steps undertaken to develop code

document is presented in next



PwC 35

3. Status of Building Regulations in Bhutan – Standards and Bodies

All BEECs refer to standards pertaining to construction, materials, testing methods that set minimum

benchmarks for the the country to follow. The country, over time, enters cycles of updates involving

various stakeholders of the sector, here specifically it is the building design and the construction

sector.

In Bhutan, the Ministry of Works and Human Settlements, the Ministry of Statistics, Local

Departments of Works, and Roads, Department of Urban Development and Housing, Bureau of

Standards and Quality Control and numerous other Central and Local Stautory, Ordinnance and

Statute forming and/ or Implementing agencies will have a key role to determine the referenced

Standards and their legal frameworks for the adoption of code (BEEC)formulation.

In this context various docments were referred to, in addition to discussions with the client. We follow

this with a synopsis of our understanding as to how the various Standards referenced extensively in

Bhutan will be impacted or will impact in return with the adoption of a BEEC.

In 2003 the Bhutan Building Rules – 2002 (BBR-2002) came into effect andare applicable for all

urban areas superseding all other rules on building regulations to facilitate and regulate a functional

and safe building construction practice, to promote a healthy living environment, to encourage

professional approach to building design and construction, to preserve and promote traditional

architecture and to promote awareness on basic minimum design standards and procedures.

The building design and construction is authorized by the ‘Competent Authority’ defined in the

Municipal Act, 1999 which is in line with how it is usually experienced in other parts of the world.

Various words, for e.g. ‘Achitect’, ‘Engineer’, ‘Commercial Building’, ‘Building Inspector’,

‘Implementing Authority’ amongst others, clearly illustrate that the building construction industry is a

well developed and professional activity that is administered locally by the Municipal Authority.

The development process for all new construction, addition and alteration including major

renovations follows a development plan in Bhutan. A project proponent must follow a permit

application process seeking permission to build with a payment of the permit fee. It is the

responsibility of the implementing agency to ensure that the applicant builds as per the prevalent

architectural guidelines, controls and minimum standards laid out by the municipal authorities or

others. A building inspector must check drawings and on field observations to ensure compliance.

After field inspection the implementing agency also issues a fit or a not fit for occupancy certificate.

The permit to build may be cancelled, revoked and the implementing agency has the authority to stop

construction in case of unauthorized construction or in case of misuse of land. And, as a last resort the

unauthorized structure may need to be demolished. The permit process and enforcement mechanism

will accommodate BEEC provisions within the realm of existing architectural control and bye-laws

administered locally by the implementing agency.

Materials used must comply with minimum standards as specified in the IS codes, PWD specifications

and other relevant codes of practice.

Architectural controls pertaining to light and ventilation needs in a ‘habitable space’ are currently but

partly addressed in BBR-2002 (as a function of the space floor area). The BEEC will have an impact

on these requirements which will need to be revised in due course.



PwC 36

Likewise, introduction of the Bhutan BEEC is likely to influence the architectural and structural

design standards referenced in BBR-2002 (below) which will need to be revised and updated. These

influences are expected to affect envelope insulation and air-tightedness of Bhutenese buildings

thereby garnering a new generation of buildings that would promote and cherishes local architecture

while improve EE and reduce the environmental and carbon footprint.

Analysis of the structure (building)

PWD structural design standards 1997

IS 1893 - 1984: Criteria for earthquake resistant design of structures

IS 456 – Code of practice for plain and reinforced concrete

IS 875 –1987: Code of practice for Design loads (other than earthquake)

NUDC/007/1985 – Timber Roof Trusses

NUDC/002/1985 – Manual for Timber Engineering Design

Design of the structure (buildings)


IS 4326 – Earthquake resistant design & construction of building




IS 800 – Design of steel structures

IS 806 – Design of Tubular Truss

IS 1904-1978: Code of practice for structural safety of buildings (Shallow foundation)

Detailing of the structure (buildings)


IS 13920 –1993: Ductile detailing of concrete structures subjected to seismic forces

IS 4326 – Earthquake resistant design & construction of building




IS 800 – Design of steel structures

IS 806 – Design of Tubular Truss

Introduction of a Bhutan BEEC influences on electrical design – for e.g. tandem wiring, sensors,

motor ratings, transformer efficiencies, high efficiency HVAC equipment, allowances for voltage

efficiency drop etc. in the local bye-laws and standards referenced in BBR-2002 will need to be

revised. Similarly standards addressing artificial lighting and mechanical ventilation BTS-012,

Electrical Installations Control BTS-010, may need a review and subsequent revision upon the

adoption of a BEEC. Finally, voluntary and best practise based policy initiatives for e.g. the Green

Building Guidelines 2013 propounded by the MoWHS will also refer tothe minimum performance

benchmarks of code components after the respective update of various Standards.

Standards addressing safety, for e.g. Fire Safety BTS-014 may take priority over BEEC influences.



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4. International review programs on BEECs 4

Building energy efficiency codes set standard requirements for how energy-efficient a building will be.

Standards may vary slightly between countries in several respects including the extent of their

coverage, the specific requirements, means of attaining compliance and the enforcement system.

Some BEEC from around the world were taken up as case studies keeping in mind the context of

Bhutan.

Parallels were drawn in terms of the country being a developing nation or the climate being similar to

Bhutan. The countries that were studied were – India, USA, Mexico, China, Egypt

The parameters studied in each of these cases were as follows:

Energy savings potential

Standards referenced

Components covered by the code (scope)

Climatic zones

Compliance structure

Relevance to Bhutan

Table 22: International review of different building energy efficiency programs

Type of buildings addressed

Building energy consumption as % of total energy consumption

Standards Referenced

Components Covered

Enforcement Compliance Structure5,6

Relevance to Bhutan

India Commercial 40% ASHRAE/ ASTM, IS, ISO

All (Envelope, Lighting, Service Hot Water and Electrical Power)*

Enforced by local jurisdiction

Mandatory in some states

Prescriptive

trade-off

Performance based

Developing nation

Warm humid climate zone similar to Bhutan

Challenges in building industry similar to Bhutan

USA Commercial 40% ASHRAE/ ASTM

All* Enforced by local jurisdictions through building permit process

Prescriptive

Trade-off

Performance based

Very Cold climate zone 7 similar to Bhutan

4 World Bank Working Paper No. 204, Mainstreaming Building Energy Efficiency Codes in Developing Countries – Global Experiences and Lessons from early adopters, Feng Liu, Anke S Meyer, John F Hogan 5 Prescriptive method of compliance offers a simple but rigid implementation methodology for meeting minimum standard requirements for each code component covered. The Trade-off approach 6 Performance method of compliance offers a flexible but complex implementation methodology for meeting minimum standard requirements for each code component covered



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Mandatory

China Commercial** 30% ASHRAE/ local standards

Not covered – Lighting, Service Hot water, Electrical power

Enforced by local / provincial jurisdictions

mandatory

Prescriptive

Trade-off

Except for region being similar, not much similarity

Mexico

Commercial 20% Mostly local standards and ASHRAE

All Enforced by local jurisdictions

Mandatory

Prescriptive Performance

based

Developing nation

Similar Latitude

Egypt Commercial** 23% ASHRAE/ local standards

All Enforced by local jurisdictions

Mandatory

Prescriptive

Performance based

Developing nation

*All – Envelope, Lighting HVAC, Service Hot water, Electrical power ** Residential is also addressed

Typical challenges faced by developing nations towards implementation and success of

the building energy codes

Cost effective energy efficiency improvements in buildings by definition are financially attractive,

usually paying for themselves within a few years. They also generate multiple co benefits, ranging

from improved comfort and health for the occupants to reduced air pollution for the general

public.

Global experiences indicate that the implementation of building energy codes is likely to have more

success in countries and localities where the construction sector is well managed in terms of

government oversight, the building supply chain is well established, the market for commercially

produced buildings is well developed, and there is broad and firm political commitment to improving

energy efficiency. Weaknesses in these areas are often the main challenges in developing countries

when they embark on efforts to implement building energy codes. Some of the key challenges faced by

the developing world towards implementation of building energy codes are as follows:

Lack of information about energy use and efficiency in commercial buildings.

Underdeveloped materials and components market for compliance, including related testing and certification capabilities.

Largely unskilled workforce that is unaware also uneducated in building energy efficiency aspects.

Subsidized residential electricity prices.

Limited ability to internalize incremental cost of EE technologies due to low income levels. With tight budget constraints for both governments and private citizens, a balanced tradeoffs is needed between more housing and more energy efficient housing. For low income countries, the priority is to maximize the floor area for a given amount of housing investment.

Absence of an Effective Government Oversight System for Building Construction - Large amount of informal building construction is outside of government oversight. Also, a robust building permit and inspection system provides a good basis for incorporating supervision arrangements for building energy codes. But its effectiveness often depends on the transparency and strength of the general governance framework, which are often weak in developing countries.

Last but not the least, Implementing modern measures to reduce/minimize building heating, cooling, and lighting loads requires a host of new design skills and approaches, new or improved materials/components and construction techniques, as well as additional supervision and inspections, compared with the prevailing commercial construction



PwC 39

practices found in many developing countries. Standards for rating and certifying these new energy efficient products will need to be established so that there is a level playing field for manufacturers to compete and take credit for their energy efficiency advances, and so that developers and designers can have confidence in the claims being made for energy efficient products. Multidimensional efforts will be needed in educating new generations of architects and engineers, training construction workers, supervisors and inspectors, and ensuring the availability and quality of new or improved materials and components.

Split incentives and principal agent problems. Split incentives prevent basing investment decisions on life cycle costs and, consequently, the realization of the benefits of energy efficiency investments. This is primarily since all investment decisions are made by developers and investors, not by those who will occupy the building later and be responsible for paying the energy bills.

Risk perception due to lack of confidence in performance of new technologies. Lack of information and knowledge. Information about energy efficiency options is often incomplete, unavailable, expensive, and/or difficult to obtain or trust. Even developers, design professionals, and contractors are not always aware of the energy efficiency technologies available

Low relevance of relatively small future costs of heating cooling and lighting - future costs of heating, cooling, and lighting services in buildings are a relatively unimportant factor, since they generally are fairly small sums on a monthly basis.

Bhutan is likely to face most of these challenges of capacity and awareness and the absence of a robust

and informed governance process. It will be in our interest therefore to develop and implement a step

by step process for code implementation that is rolled out over time in a manner such that the

building supply chain is simultaneously made ready to receive the code.



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5. Climate Zones determination for Bhutan

Bhutan's climate is as varied as its altitudes and, like most of Asia, is affected by monsoons. Western

Bhutan is particularly affected by monsoons that bring between 60 to 90 percent of the region's

rainfall. The climate is humid and subtropical in the southern plains and foothills, temperate in the

inner Himalayan valleys of the southern and central regions, and cold in the north, with year-round

snow on the main Himalayan summits.

Figure 17: Climate zone for Bhutan : Geographic regions overlaid on the administrative regions of Bhutan

Temperatures vary according to elevation. Temperatures in Thimphu, located at 2,200 meters above

sea level in west-central Bhutan, range from approximately 15°C to 26°C during the monsoon season

of June through September but drop to between about -4°C and 16°C in January (see table 22,

Appendix). Most of the central portion of the country experiences a cool, temperate climate year-

round. In the south, a hot, humid climate helps maintain a fairly even temperature range of between

15°C and 30°C year-round, although temperatures sometimes reach 40°C in the valleys during the

summer.

Further, Bhutan climate and weather was studied along with the Koppen climate classification system.

Similar climate zones to those in Bhutan were considered in detail. This exercise resulted in

determining climate zones referenced elsewhere in other BEECs which was relevant for the Bhutan

context, and therefore the Bhutan BEEC.

While the Köppen classification system doesn't consider temperature extremes,

average cloud cover, number of days with sunshine, or wind into account, it's a good

representation of our earth's climate. With only 24 different sub-classifications,

grouped into the six categories, the system is easy to comprehend.7 The Köppen and its

derivative systems are simply a guide to the general climate of the regions of the planet,

the borders do not represent instantaneous shifts in climate but are merely transition

zones where climate, and especially weather, can fluctuate.8

1 Rosenberg, M., http://geography.about.com/od/physicalgeography/a/koppen.htm; December, 2013 8 Rosenberg, M., http://geography.about.com/od/physicalgeography/a/koppen.htm; December, 2013

http://geography.about.com/od/physicalgeography/a/koppen.htm

http://geography.about.com/od/physicalgeography/a/koppen.htm



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It was concluded that Bhutan has four distinct (Köppen-Geiger, 2006) climate classification types

within its administrative boundaries. These are:

ET (Tundra),

Dwd/ Dwc (Snow climate, dry winter, Extremely Continental or Cool Summer, Cold Winter)

Cwb (Warm Temperate with Dry Winter, and Warm Summer)

Cwa (Warm Temperate with Dry Winter, and Hot Summer)

For specific applicability to the Bhutan BEEC, a suitable (reference) climatic zone map defining the

climatic zone boundaries (Standard) could not be found. Such an exercise is essential for the code.

However, based on the findings it was determined that the three main geographic regions will have a

strong bearing on the determination of the (yet to be decided) boundary for the applicable climatic

zones of Bhutan BEEC. Therefore following is deduced for Bhutan:

Table 23: Bhutan specific Köppen-Geiger climate classification

Bhutan specific Köppen-Geiger climate classification

Climate zones characteristic in view of the three primary geographical regions (Alpine, Mid-Montana and Sub-tropical)

Determination for Referenced Standard for the Building Envelope Chapter for Bhutan BEEC

ET (Tundra), Very cold ASHRAE/ ANSI 90.1-2007, Zone 7

Dwd/ Dwc (snow climate with dry winter, extremely continental or cool summer, cold winter)

Cwb (warm temperate with dry winter, and warm summer)

Cold ECBC 2007, Cold

Cwa (warm temperate with dry winter, and warm summer)

Warm and humid ECBC 2007, warm and humid



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6. Construction Practices

6.1. Integration of modern construction designs with traditional features

With the unprecedented growth in construction techniques and materials, a day to day improvement is

required for achieving a balanced development. According to the climatic zones specified in previous chapter

there are many construction practices to be considered:-

6.1.1. Orientation and shape of the building

Bhutanese buildings adhere to the contemporary principles of sustainability, and are oriented in such a way

so as to reduce heat losses and maximize passive solar gain. For instance9, within Bhutanese villages, 'houses

and trees are arranged in such a way as to provide each other with maximum wind shelter'.

It is also interesting to note the use of thermal mass and wind sheltering techniques to create ‘outdoor hot-

zones10’ both between buildings within a cluster, and also around these building by means of a 2m high

boundary-type wall11.

12 Figure 18: Traditional building in

Bhutan (depicting a rabsel on the side of

the wind direction)

Individual buildings generally follow a typical layout:-firstly there is a wall made up of rammed mud which

runs along the back. This wall generally faces the north direction. This section of the building has the largest

openings. In order to allow the maximum percolation of light, the most prominent rooms are located in the

area of the building13.

“A long experience with earthquakes as well as tremors has made the Bhutanese people careful14” and hence

along with adherence to traditional architectural principles, buildings in Bhutan incorporate many features

characteristic of a good seismic design. They are invariably symmetric in plan with symmetric openings, an

important precautionary measure in seismic design1516.

Table 24: Different building materials and their attributes - Examples from Bhutan

9 DoWHR, 1993:188 10 DoWHR, 1993:227 11 DoWHR, 1993:205 12 Source: - http://richardarunachala.wordpress.com/2013/10/03/bhutan-traditional-arts-and-the-tashichhoe-dzong-

in-thimphu/ 13 DoWHR, 1993:195 14 DoWHR, 1993:201 15 Arya, 2007:101 16 House plans are also generally square or rectangular, as advocated by Minke (2001:9)



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Materials Attributes Building element

Field study Conclusion

Boulders, rocks, stones

Provide insulation

Cost effective

Thermal mass

Locally available

Good life span

Foundation

Plinth

Walls

Roofs

Most of the traditional foundations were huge due to load bearing construction.

17 Stone foundation

18

With some advancement stones should be used for future construction.

Soil or mud Good thermal mass

Cost effective

Can give insulation

Locally available

Life span (depends)

Walls

Roof(internally)

Several heritage buildings are made from rammed earth.

Due to recent earthquakes, these buildings were not in a good condition.

In certain places, mud was used in the roof, particularly in Dzongs.

19

20

It must be retained if proper skilled sets are provided.

Timber or wood

Thermal mass

Cost effective

Provides insulation

Locally available

Good life span

Internal walls

Rabsel

Fenestrations

Roofs

Cornices

Stairs

Internal walls of rural houses and resorts used wood. However, resorts an added insulation of glass wool.

Many of the hotels, urban and rural houses preferred wooden windows of different shapes and sizes according to their requirements.

Many resorts and urban houses incorporated wooden roofs. However, resorts used extra insulation.

21 22

23

Since it is not a renewable material, and forests are affected, some alternative materials need to be taken into consideration

Bamboo Cost effective

Locally available

Good life span

Frame structure

Wall

Roof

Stairs

An urban house demonstrated a proper construction of framed structure with bamboo.

Upper stories of hotels and urban as well as rural houses constructed an Ekra wall with no additional insulation.

24 A 100m2 building in Tingtibi, Zhemgang district, Designed and constructed by INBAR, the Ministry of Agriculture and Forestry of Bhutan.

A good alternative for bamboo

Proper opting of bamboo can be a task

17 Source: A sustainability approach to standards for rammed earth construction in Bhutan-Zareen 18 Source: Energy audit study by PwC 19 Source:www.mdpi.com/journal/sustainability 20 Source: Energy audit study by PwC 21 Source:http://ngm.nationalgeographic.com/ngm/photo- ontest/2011/entries/74906/view 22 Source: Energy audit study by PwC 23 Source: Energy audit study by PwC 24 Source:http://www.inbar.int/2012/01/bambooconstruction-bhutan/



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Glass Not cost effective

Good insulation (optional)

Locally available

Good life span

Fenestrations

Modern construction designs of institutions, hotels and offices chose glass glazing.

Glass was used for almost all windows.

25 An attempt to integrate traditional Bhutanese architecture with modern construction materials. 26

For certain multi- storey buildings, glass can be a good option according to climatic zones.

Cannot be used large numbers as it is not cost effective

Bricks Good thermal mass

Cost effective

Insulating

Can be locally Available

Good life span

Walls Wall thickness varies according to building type:institutions, rural and urban houses measuring 420 mm, hospitals, resorts and hotels measuring 305 mm, and offices with a measurement of 228 mm.

No insulation was provided, particularly for the brick walls.

Fenestration sizes increased due to good load bearing capacity.

27 New apartment building with the incorporation of traditional architectural features.

If made locally available, it can prove to be a good alternative for rammed earth construction.

Bricks, Walls, foundation plinth and RCC

Good thermal mass

Not cost effective

Available on some places

Good life span

Earthquake resistant

Framed structure

Foundation

Roof slab

Buildings such as offices, hospitals and hotels are built from RCC

In some multi-storied hotels, flat slabs were opted, with a thickness of 200 mm.

28 New construction with traditional architectural features incorporated at the facade level

Good strength characteristic, thus if production is made locally, being a standard material it can prove to be very useful


Aluminum Not cost effective

Not available locally

Good life span

Fenestrations Most of the offices, hotels, resorts and hospitals used aluminum for windows as well as glazing’s.

Size and shapes varied according to the individual building requirement.

29

High energy consuming material.

Recyclable material.

25 Source: Sonam, Historic Districts as an alternative approach to preserve the Bhutanese Architectural Heritage, MIT 26 Source: Energy audit study by PwC 27 Source: Sonam, Historic Districts as an alternative approach to preserve the Bhutanese Architectural Heritage, MIT. 28 Source: Sonam, Historic Districts as an alternative approach to preserve the Bhutanese Architectural Heritage, MIT 29 Source: Energy audit study by PwC



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Steel Cost effective

Not available locally

Good life span

Roof

Walls

Glazing frame

Stairs

Not much of steel construction was found in Bhutan

Elements such as roof trusses and the stairs of urban houses were constructed using steel.

30 Aman Resort, Paro. Unique Bhutanese architectural features incorporated into modern amenities - Meeting the increasing demand for tourism infrastructure

Not preferable if cost is considered

Can be a good material for an earthquake resistant structure.

G I Sheets Thermal mass

Not cost effective

Insulation is needed

Locally available

Good life span

Roof Mostly, hotels and rural houses used GI sheets for their roofs.

31 Bhutan Elder Sangha Sanctuary, Bhutan

If used as a roof according to the climatic conditions, during the day it can get hot, while during the night it may release heat as quickly as possible.

30 Source: Sonam, Historic Districts as an alternative approach to preserve the Bhutanese Architectural Heritage, MIT 31 Source: http://www.tsao-mckown.com



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6.2. Building element construction

6.2.1. Foundations

Traditionally, foundations in Bhutan were always strip footings made from materials such as rubble

masonry and mud mortar, although cement mortar is now often being used. Some craftsmen insisted

that if cement mortar was used, a layer of plastic sheeting (to act as a damp proof course) needs to be

placed in between the top of the stonework and the mud. However, this was not a universal practice.

The key function of footings32 at the base of the wall is to protect the earth wall from moisture ingress,

and hence, although any simple mass footing can be used (such as concrete, masonry, cement

stabilized rammed earth), a continuous damp-proofing barrier must also be provided. The design of

the foundations for lightly loaded low- rise rammed earth buildings can follow rule of thumb

guidelines as prescribed by Walker and Maniatidis, 2003:65.

The dimensions of the foundations measured during site visits and obtained through interviews with

the skilled craftsmen were remarkably consistent and are summarized in Table 25. They have also

been checked against, and found to be consistent with, the dimensions found in traditional

architecture33.

Table 25: General guidelines for foundation dimensions in Bhutan

34

The dimensions of Bhutanese foundations were all found to be larger than those recommended in

various codes where the foundation depth as well as its width never exceeds 400 mm. A robust

drainage system is essential in protecting the rammed earth walls, and Bhutanese practice on this

aspect matched the guidance given by various national codes.

6.2.2. Walls

The minimum wall thickness found in Bhutan was 50 cm. Apparently, in this case, craftsmen were

given a design wherein the walls measured only 30 cm thick, due to which they feared a collapse,

and hence increased their thickness. Generally, the minimum thickness found was to be 60 cm (2 feet)

and greater, if the building was more than two storeys.

It is a standard practice in Bhutan to taper the walls of the buildings greater than two storeys, and

hence the wall thickness at the bottom of large buildings can reach over 1 m. Although craftsmen

explain the need for tapering as being the prevention of bulging and enhance the aesthetic value of the

buildings, Arya (2007:101) notes that tapering walls provide better stability against lateral forces and

hence are highly advantageous in seismic areas.

32 According to Walker et al. (2005:61) 33 DoWHR, 1993:191 34 *Imperial units are given since in practice the craftsmen invariably gave the measurements in feet and

inches.



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Figure 19 : Tapering walls at Bhutan35

6.2.3. Rabsel

Rabsel is a timber structure constructed with a series of vertical as well as horizontal members usually

found in the upper storeys of traditional building structures with a symmetrical distribution of infill

panels called ekra and window openings.

It is usually lighter than any other structure, and hence is usually found on the upper levels of a

traditional building in order to reduce its structural load on the load bearing walls. The hierarchy and

entitlement of these elements are significant in traditional Bhutanese architecture.

Figure 20 : Rabsel in walls

35 Source: Ministry of Works and Human Settlement (MoWHS)



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Elevation and a section of a typical rabsel36. Types of rabsels based on the geography of the region and

the height of the structure:-

Parop rabsel

Go-chham Thognyim rabsel

Lobur rabsel

Drey-Zhu rabsel

Gomang rabsel

36 (source: Historic Districts as an alternative approach to preserve the Bhutanese Architectural Heritage by

Sonam Gayleg)



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Nimchong rabsel

Shamig- ekra wall(bamboo frame)

Figure 21 : Types of rabsels used in walls in Bhutan37

6.2.4. Openings -Doors and windows

Windows and doors are traditionally kept to a minimum in Bhutanese buildings with the timber and

ekra frontage on the upper floors providing the light and ventilation required. They therefore

invariably comply with both load bearing and seismic design guidance which describes the maximum

total length of openings, distance to corners etc.

The openings are narrow, tall and divided into two or more layers and are usually found in the lower

part of the building. In a traditional building, the structural walls are usually rammed earth and stone

masonry which are load bearing walls and hence the openings at the lower level are small and narrow.

Payab windows Geykar window

Figure 22 : Traditional windows in Bhutan38

37 Source: Ministry of Works and Human Settlement (MoWHS) 38 Source: Ministry of Works and Human Settlement (MoWHS)



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Mago (Door)

This is the main entrance door of a building in Bhutan which has all the traditional details such as

Dhung, Pedma, Choetseg and bogh.

Figure 23 : Traditional windows in Bhutan39

6.2.5. Kachhen and Zhu

In Bhutanese buildings, kachhen is the timber column that is usually tapered with intricate carvings,

while zhu is the intermediate bow shaped timber bracket between the column and the beams above.

The bracket, shaped like a bow, reduces the length of the beam so as to increase the load bearing

capacity.

Figure 24 : Kachhen and zhu timber columns for load bearing in ceilings40

39 Source: Ministry of Works and Human Settlement (MoWHS) 40Source: Ministry of Works and Human Settlement (MoWHS)



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6.2.6. Cornices

Cornices are usually a part of the rabsel and form an integral element of the traditional Bhutanese

architecture.

Proportion: If width of the bogh is ‘b’ then the thickness of bogh a is ‘b’ plus 25 mm. The minimum

projection of a bogh equal to a band maximum ‘a’. Minimum spacing of ‘b' between these boghs is

1.75 b and maximum 2 b. The projection ‘c’ of the ohung and pedma is normally equal to b. The

minimum size of the bogh for the rabsels/ shall be 115 x 140 mm and maximum 150 x 175 mm.

Pictorial representation of the proportions of cornices41 Concrete cornice42

Figure 25 : Cornices in the walls

6.2.7. Roof

Heavy rainfall received during the summer and monsoon season in Bhutan, necessitates a

sloping roof in order to guarantee quick water discharge.

The sophisticated nailless roof construction is visually broken away from the true building. Its

structural design conveys the expression of a flying roof.

The space below the roof offers a welcome opportunity to dry skins, hay, etc.

The roof floor is insulated with a rammed earth layer with a thickness of approximately 10 cm.

The standard roof pattern is a pitched timber shingle covering, which is fixed through the

weight of stone boulders that are laid down over laths.

The slope of the pitched roof is approximately 12 to 15 degrees. A steeper roof is not possible

since the stones that fix the shingles will roll-off the roof.

41 Source: Traditional architecture guidelines by the Department of Urban Development and Housing 42 Source: Ministry of Works and Human Settlement (MoWHS)



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Types of Roofs:

Gable roof

Hip roof Lean to roofs

Figure 26 : Types of roofs in Bhutan43

43 Source: Ministry of Works and Human Settlement (MoWHS)



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7. Key inputs or the Approach for the EE plan in buildings

Having surveyed, researched and understood the key construction practices adopted for buildings in

Bhutan, one can clearly conclude that with the growing urban sector, there will soon be a need to

retain vernacular building architectural practices in the country along with the deployment of

energy-efficient measures in the new buildings that are coming up. It is imperative that passive design

measures are to be introduced in all new housing as well as commercial developments in order to

reduce the load in buildings, and all active measures are to be made energy-efficient.

This can be best achieved by the following ways:

By following an integrated design approach and an efficient and integrated design process of

first reducing building loads and thereafter using energy efficiency measures.

Developing a set of green guidelines, retaining the traditional knowledge in the area of

construction, and recommending a series of passive design strategies for households and

other constructions.

After a sensitive design is achieved one can look at incorporating energy efficient measures to

further reduce the energy use in buildings. These are best achieved by recommending

Building Energy Efficiency Codes that address various active measures deployed in a building

including HVAC, lighting, envelope insulation, glass and fenestration, power and hot water

requirements.

Initiate policy measures such as the Appliance Standards and Labeling (S&L) program to

reduce energy consumption in domestic as well as commercial segments.

Initiate a program for improving firewood ‘Bukhari’ systems



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8. Efficient and Integrated Design Processes

A whole building design consists of two components: an integrated design approach and an integrated

team process. The integrated design approach brings together all the players of the building

stakeholder community, while the technical planning, design, and the construction team is to look at

the building design as a whole.

Whole building design in practice, also requires an integrated team process in which the design team

and all affected stakeholders work together throughout the project phases, and evaluates the design

for aspects such as cost, quality of life, future flexibility, efficiency, the overall environmental impact,

productivity, creativity, and ways in which the occupants will be enlivened. The whole building

process draws from the knowledge pool of all stakeholders across the life cycle of the project, right

from defining the need for a building, through processes such as planning, design, construction,

building occupancy, and operations.

When executed in the right manner, the integrated or whole building design process can result in cost-

effective buildings with significantly better performance as compared to business as usual. 44

Figure 27: Different stakeholder involved in building design

44 Whole Building Design Guide http://www.wbdg.org/resources/lcca.php

http://www.wbdg.org/resources/lcca.php



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Energy saving opportunity45

Energy savings can be achieved through technical improvements made to buildings and energy

consuming equipment so as to reduce energy waste (thereby increase energy efficiency) and by

conservation behaviours that do not necessarily compromise desired energy services (such as turning

out the lights when one leaves the room or having thermostats automatically adjust the

temperatures for unoccupied hours). From another perspective, it is important to address the issue of

energy waste during occupied as well as unoccupied hours. Proactive conservation behaviours as well

as robust operations and maintenance practices are critical for achieving the intended energy savings

of any technical improvements. Technical energy efficiency improvements that reduce energy

consumption in buildings fall under the following three broad categories:

Reducing the load,

Utilizing efficient systems to serve the load, and

Substituting with renewable energy where possible

Reducing the load

There needs to be a reduction in space heating, space cooling and lighting loads through energy

efficient building and site designs as well as their proper implementation. There are different design

techniques for reducing building envelope heat losses. In the climatic conditions dominated by

heating loads, it is important to isolate the building from its environment by a well-insulated and

airtight building envelope. In regions with cool climates, it is essential to minimize the daytime solar

gain through windows and lightweight roofs and walls. In other more moderate climates, the

significance of thermal insulation is not as prominent, and hence it is important for the building

envelope to be relatively responsive to the environment so as to efficiently address the varying needs

for heating, cooling, ventilation, and lighting.

Light reflective roofs and exterior walls are relatively low-cost measures for reducing cooling loads in

warm or hot and dry climates. Architectural details of individual buildings (form, orientation, and

shading, for example), landscaping, and ways in which buildings are oriented in a particular

construction site also affect the heating, cooling, and lighting loads and need to be considered within

the site planning and building design process. Water heating loads can be reduced through the use of

low flow plumbing fixtures. Lighting energy use can be reduced by day lighting design techniques

with light shelves that bounce the daylight further into a space, combined with automatic lighting

controls to dim or turn off electric lights in response to daylight conditions. The potential for cost-

effective reduction of heating and cooling loads using well-developed designs and broadly adopted

technologies is huge .

Utilization of efficient systems to serve the load

There is also a need to increase the efficiency of space heating, space cooling, ventilation, water

heating, appliances, other electric and electronic equipment, and lighting through technical

innovation and improved operational performance. Energy efficiency of HVAC systems is dealt with

both at the building design stage (proper sizing and selection of highly- efficient units that minimizes

the life cycle cost, and installation of controls) as well as through building commissioning and

improving operations and maintenance. With affordability levels showing a rise, the number of

appliances is also rising within household buildings in the developing nations. Utilization of energy

efficient appliances will further help curtail energy costs. Regulated standards and a labelling program

45 World Bank Working Paper No. 204, Mainstreaming Building Energy Efficiency Codes in Developing Countries – Global Experiences and Lessons from early adopters, Feng Liu, Anke S Meyer, John F Hogan



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for appliances, such as those in India and China, can ensure the import and use of efficient appliances

in Bhutan.

Substituting renewable energy

Bhutan needs to utilize renewable energy resources for energy services within buildings. This refers to

technologies that utilize natural heat sources and sinks directly (solar water heater, for example) or

indirectly (heat pump technology, for example) so as to reduce the consumption of fossil fuels and, at

the same time, the life cycle costs of relevant energy services. The suitability of such applications often

depends on site- specific conditions.

An energy efficient building design; implemented together with efficient heating and cooling

systems/equipment, represents the largest technical potential for energy savings in residential,

commercial, and public service buildings.

Life cycle cost analysis46

Design decisions must consider the life cycle cost for the entire building or project, and not just the

first cost considerations for an individual or isolated system or measure.

A life-cycle cost analysis (LCCA) is a method for assessing the total cost of facility ownership. It takes

into account all the costs of acquiring, owning, and disposing a building or a building system. LCCA is

especially useful when the project alternatives that fulfil the same performance requirements, but

differ with respect to initial and operating costs, have to be compared in order to select the option that

maximizes net savings. For example, LCCA will help determine whether the incorporation of a high-

performance HVAC or glazing system, which may increase the initial cost, but result in a dramatically

reduced operating and maintenance costs, is cost-effective or not.

46 Whole Building Design Guide http://www.wbdg.org/resources/lcca.php

http://www.wbdg.org/resources/lcca.php



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9. Green Building and Passive Guidelines

Building energy efficiency is primarily addressed by reduction in the loads and then by improvising

the systems’ efficiency levels. Passive design is followed by active design measures as the globally

accepted way of offering energy efficient building design. Here, a well developed code of its kind is

being referenced to namely, the Passivhaus Standard, Europe. It is expected that architects as well as

design engineers of the new generation of Bhutanese buildings will utilize this resource and

incorporate and customize these passive principles into their respective designs. Guidelines, if utilized

in conjunction with the code, are expected to yield greater success and uptake of the code amongst the

implementing community.

Figure 28: Passive/ bio-climate design strategies

9.1. Alternative Building Materials

With a boom in infrastructural development activities in Bhutan, high-embodied energy materials

such as cement, steel, bricks, glass, etc. are being utilized . Apart from being high embodied materials,

many of the conventionally used materials have become expensive , due to these materials being

imported from the neighboring countries. Therefore, there is an urgent need to look out for

alternative materials which are preferably available or manufactured locally. From an environmental

and poverty perspective, adoption of locally available low-embodied energy materials is highly

desirable in the country.

Some of the alternative building materials or technologies which may be consciously promoted in the

country are as follows:

1. Compressed stabilized earth blocks

2. Hollow interlocking blocks

3. Bamboo



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Alternative materials

Material Attributes Compressed stabilized earth blocks

47 CSEB blocks

Good thermal mass

Good insulation

Less polluting

Alternative for bricks.

Hollow interlocking blocks

48 Figure: A demonstration project using HI CSEB in

jemin, Bhutan

Good thermal mass

Energy efficient and eco friendly

Biodegradable materials

Cost effective.

Lateral load resisting capacity

Alternative for bricks

Bamboo

49

Biodegradable materials

Cost effective

Can be fabricated


Good insulation

Allows a good fenestration space.

Replacement for timber and prefabricated sheets or tin sheets.

47 Source:www.projectneighbors.org 48 Source: Presentation by Jigme Tenzin at the 6th Annual Engineering Conference 49 Source: http://www.inbar.int/2012/01/bambooconstruction-bhutan/Bamboo in Bhutan:



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Compact Construction

In general, it is desirable to design buildings with high compactness. The more the compactness, the

lower is the heating demand. A design with medium-high compactness in required during the summer

season, because the cooling demand will be reduced. High compactness can be sacrificed sometimes

in order to have a higher surface oriented towards the south. In this situation, an intermediate

solution can be adopted with medium compactness.

9.2. Orientation

As far as possible, the longer axis of the building needs to be oriented in the east –west

direction.

Buildings needs to be spaced in such a way that they must not shade each other or block the

sun during winter.

9.2.1. Space orientation

Direction is such that it trap maximum solar energy during winter months.

The living spaces of a building must be designed as day lit spaces.

The non-living spaces, that is, the stair cases, washrooms, stores and garages may be planned

preferably on the northern side so as to provide as buffer to reduce heat loss from the living

spaces.

In warm and humid climate regions (the southern part of the country), high level of cross-

ventilation is required in buildings in order to maintain thermal comfort. Small size windows

need be placed on the windward side, while larger windows must be placed on leeward side

for facilitating direct ventilation through pressure difference.

In cold areas, all the main living areas, where applicable, are best orientated towards the

south so as to receive the maximum natural benefits of the sun, while other areas such as the

washrooms, corridors, etc., can be located in the northern side.

Wall orientation

Orientation is a parameter defined for each one of the external walls of the building. The orientation

must be obtained from the angle between the normal to the wall and the north direction. Accurate

orientation must have an adequate level of heat loss area oriented towards the south. This will

contribute to increased heat gains due to solar radiation, and it is mandatory in this case to design the

southern walls with a high percentage of glazing. During the summer season, this measure requires a

well-designed system of solar control because in other cases, the building or at least the adjacent zone

will be overheated. East and west orientation are avoided because the level of radiation in these

directions is low during winter, and also in the summer season, solar control is much more

complicated than in south orientation.

Window and door orientation

The northern facade must have minimum door and window openings.

The southern facade needs to have maximum glazing in order to capture maximum solar

heat during winters.



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It is recommended that for a new construction, glazing must be in proportion to the total

surface area of the wall and preferably must not exceed more than 50% in the mid-altitude

region, that is, 1500 to 2,200 m, and not more than 70% in the high altitude regions, that is

2200 m and higher.

The size and position of doors, windows, and vents within the envelope must be evaluated

after a careful consideration of aspects such as day lighting, heating, and ventilating

strategies.

The main windows and balconies need to be designed to face the south and south-east

direction for solar gain. North-facing windows can be limited since there is no solar gain

towards this direction.

The percentage of glazing surface related to the floor area needs to be around 20% to the

south, and 5% to the north. A good orientation of the building is a goal for all climatic

regions.

Insulation

Ground Insulation

The ground temperature two to three meters deep inside the earth, is only slightly higher than the

annual average air temperature during the whole year. The same is true below floor slabs: Diurnal, but

even annual changes in temperature occur mainly near the boundary.

Depending on the climate and general building properties, insulation of the floor slab or the basement

can be necessary, useful or counterproductive.

However, insulation is usually thinner than that present in building elements adjacent to the ambient

air where the heating energy demand can already be minimized by other means, insulation of the floor

slab as well as the basement can be omitted, using the ground as a heat sink during the summer

season.

Insulation can be placed below the floor slab if the material can resist factors suchas pressure and

humidity; it is also possible to install the insulation above the floor slab. A snapshot of ground

insulation is presented at Figure 29.

Figure 29: Ground Insulation50

50 Source: the passivhaus standard in European warm climates: design guidelines for comfortable low energy

homes.pdf



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Figure 30: Plinth protection provided by sloping paving for drainage channel51

Figure 30 shows that a proper drainage system can prevent water logging near the building

foundation and hence keep the soil beneath free from any climatic disturbance. Therefore, it provides

a hand in ground insulation.

Wall insulation

Environmentally sensitive insulating materials, made from recycled materials such as cellulose or

mineral wool, need to be considered, if such items meet the project’s performance as well as budgetary

criteria.

Insulation of the walls reduces the average heat flow through the wall construction. The effect is

characterized by the U-value, given in the formula W/(m2K), which signifies the heat flow through

one square meter of the wall area at a constant temperature difference of 1 K (= 1 °C). Although, there

are variations in the heat flow due to the constantly changing boundary conditions, the U-value

represents the average heat flow through the wall.

Good insulation of walls limits heat losses during the winter season and increases the interior surface

temperatures, thus increasing thermal comfort and reducing the risk of damages due to excess

humidity.

Sufficient wall insulation is therefore indispensable for the reduction of heating energy demand in

winter. Well-insulated walls also help to reduce the amount of heat that is transferred into the

building during the summer heat waves. They support both natural ventilation strategies as well as

energy-efficient active cooling concepts, whenever the interior temperature drops below the daily

average of the exterior surface temperature.

51 Source: A sustainability approach to standards for rammed earth construction in Bhutan by Zareen Sethna

(CL)



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Figure 31: Snapshot of a 40 cm gable wall compound insulation system and a porous ceramics brick52

Roof insulation

Good insulation of the roof is necessary in order to reduce the winter heating energy demand. Concerning insulation thickness, there are usually less constructive constraints in the roof than in the walls. Therefore, roof insulation is typically dimensioned thicker than wall insulation. Well-insulated roofs are also a good solution for reducing the summer heat load.

Insulation in inclined roofs can be applied between roof rafters or on top of the rafters below the tiles. For concrete roofs, exterior insulation above the concrete is useful. With modern, water-resistant insulation materials, the lifespan of the main waterproofing layer can be increased by installing it between the insulation and the concrete.

Figure 32: An inclined roof with insulation with respect to the rafters and highly insulated concrete roof construction53

52Source: the passivhaus standard in European warm climates: design guidelines for comfortable low energy

homes.pdf 53 Source: the Passivhaus Standard, European Union warm climates: design guidelines for comfortable low

energy homes.pdf



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Thermal mass

Thermal mass, coupled with the interior of the building, can be of a considerable advantage both in

the summer as well as winter season. During summer, it can be used to limit the upper daytime

temperature and thereby reduce the need for cooling. This effect can be enhanced by coupling the high

capacitance material with night time convection to pre-cool the thermal mass for the following day.

Figure 33 gives the snapshot for a thermal mass in a building.

Figure 33: Snapshot for thermal mass in a building54

Preference must be given to use local materials that is stone, slate and mud and other such

construction practices so as to reduce heat loss and maintain adequate thermal comfort during peak

the peak winter months.

Figure 34 : Pictorial representation of radiation of heat during day and night55

Thick stone masonry or rammed earth walls may be used to serve as thermal mass in order to the

building and also to absorb solar gains to heat the building. Materials such as tiles, stone, or masonry

floors need to be considered for heat storage.

54 Source: the Passivhaus Standard, European Union warm climates: design guidelines for comfortable low

energy homes.pdf 55 Source: the Passivhaus Standard, European Union warm climates: design guidelines for comfortable low

energy homes.pdf



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Figure 35: Construction from rammed earth56

Integrating solar heating systems

Passive solar heating systems such as solar air heating, water heating, sun space, solar walls, space heating green houses and solar trombe wall, etc. shall be integrated within the building design wherever possible on the southern side, so as to allow maximum direct solar access to these systems.

The suitability of space heating systems is to be installed or incorporated within the design of a solar passive building and needs to be decided by either the architect, engineer, designer or solar expert in accordance with the building site, climate and space heating requirements.

Trombe wall

A south-facing masonry wall covered with glass, spaced a few inches away. Sunlight passes through

the glass and is absorbed and stored by the wall. The glass as well as the airspace keeps the heat from

radiating back to the outside. Heat is transferred by conduction since the masonry surface warms up,

and is slowly delivered to the building, a couple of hours later.

56 Source: http://www.raonline.ch/pages/bt/cult/bt_archi0201.html



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Figure 36: Pictorial representation of working of Trombe wall57

They provide carefully controlled solar heat to a space without the use of windows and direct sunlight,

thus avoiding potential problems from glare and overheating, if thermal storage is inadequate. The

masonry wall is part of the building’s structural system, effectively lowering costs. The inside, or

discharge, surface of the Trombe wall can be painted white to enhance lighting efficiency within the

space. However, the outside large dark walls sheathed in glass must be carefully designed for both

proper performance and aesthetics.

The characteristics of a solar wall as compared to a direct gain window are as follows:

Its efficiency in collecting solar heat is not as high as a direct gain window of the same size.

The night heat losses are less than for a direct gain window.

The structure is very simple without —fans, ducts, controllers.

It does not provide day lighting or views as a direct gain window would

The inside surface of the wall can be used to some extent, but should not be covered with

anything that reduces heat transfer from the wall to the living space.

Depending on the current wall construction, it may be easier to retrofit a solar wall than to

retrofit a direct gain window because , no wall structural members are cut.

Advantages

Comfortable heat: It radiates in the infra red, which is more penetrating and pleasant than

traditional convective forced air heating systems.

Passive: It has no moving parts and essentially no maintenance.

Simple construction: This is relatively easy to incorporate into building structure as an

internal or external wall. Materials (masonry, concrete) are relatively inexpensive.

Effective: It can reduce heating bills by large amounts.

57 Source: http://suryaurza.com/trombe-wall/



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Figure 37: Working of Trombe wall in respect to day and night58

Sun spaces

A sunspace or solarium is a combination of direct and indirect gain systems. Solar radiation heats up

the sunspace directly, which, in turn, heats up the living space (separated from the sunspace by a mass

wall) by convection and conduction through the mass wall.

The basic requirements of buildings heated by sunspace are as follows:-

A glazed south facing collector space attached yet separated from the building and living space is separated from the sunspace by a thermal storage wall

Sunspaces can be used as winter gardens adjacent to living space

Figure 38: Trombe wall vs. sun space59

Important considerations for sunspace design are as follows:

In cold climates, double glazing reduces conductive losses through the glass to the outside.

Insulated panels, shades, or blinds are more important for sunspaces than for Trombe walls, as sunspaces are sometimes occupied.

As with Trombe walls, the darker the internal surfaces of the sunspace, the more effectively the thermal mass can store heat during the day.

Do not overpopulate conservatories with vegetation, as foliage can reduce the system's heat capture by significantly shading the floor and wall.

58 Source: http://suryaurza.com/trombe-wall/ 59 Source: http://suryaurza.com/trombe-wall/



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Natural ventilation

The amount of ventilation required varies according to the season. In order to provide for our

physiological needs and to maintain internal air quality, a minimum of 8-10 liters per person per

second is required.

Figure 39: Types of ventilation that can be implemented in Bhutan60

The warm and humid climate regions (southern part of the country), require a high level of cross

ventilation in the buildings to maintain the thermal comfort. Small size windows should be placed on

the windward side, while larger windows should be placed on the leeward side for facilitating direct

ventilation through pressure difference.

Infiltration and air tightedness

Leaky building envelopes cause a large number of problems, particularly in cooler climates or during

cooler periods. Airflows from the inside to the outside through cracks and gaps result in a high risk of

condensation in the construction. Infiltration results in a penetration of cold air, which makes

inhabitants uncomfortable. Cold air infiltration also increases the temperature difference between

different storeys of a building. Finally, using cracks in the building shell for ventilation purposes does

not provide sufficient air change unless the envelope is so leaky that drafts and discomfort occur

frequently.

Good air tightness is mainly achieved by appropriate design.

On the contrary, airtight buildings without ventilation

systems run the risk of bad indoor air quality and excess

humidity.

Figure 40: Sealing tape for plaster for air tightness61

60 Source: the Passivhaus Standard, European Union warm climates: design guidelines for comfortable low

energy homes.pdf 61 Source: the Passivhaus Standard, European Union warm climates: design guidelines for comfortable low

energy homes.pdf



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10. Building Energy Efficiency Code62,63

The Building Energy Efficiency Code of Bhutan has been modeled on the Energy Conservation

Building Code of India and partly also references ASHRAE/ ASTM/ ISO and IS standards and Bhutan

Green Building Guidelines for the various parameters for which it sets out performance benchmarks.

Although, if there is a need to establish more accuracy, a larger code development process would be

required.

More importantly, for the Code to be referred to as a legal document by the building, implementing

and enforcement community of Bhutan, there needs to be in existence an Act/ a Law of the land

thereby providing the BEEC document and a nodal agency governing it the legal framework to

administer further developmental strengthening, adoption, implementation and enforcement in the

future.

The Bhutan BEEC document presented in the Annexure L(and as modeled on the lines of ECBC) is an

important step towards promoting energy efficiency in the building sector. It is written in code

enforceable language. We hope to address the views of the manufacturing, design and construction

communities expected to be similar to the Indian context -- as an appropriate set of minimum

requirements for energy efficient building design and construction. The purpose of the BEEC

document is to provide the minimum requirements for energy efficient design and construction of

buildings and their systems. These buildings can act as ready reference for various stakeholders as

well as a base document for further developmental strengthening.

As far as the numerical references to the various code component benchmarks (read Envelope,

Lighting, HVAC etc.) are concerned, this BEEC document references ASHRAE 90.1 and ECBC 2007

numerical values for the envelope section. All the other Code components refer to the ECBC 2007

numerical values and compliance approaches since the building design and construction market

realities of both the developing nations, India and Bhutan are closely linked and similar.

Figure 41: Methodology for building energy code compliance

62 Energy Conservation Building Code User Guide, 2009, Bureau of Energy Efficiency, India 63 Energy Conservation Building Code, 2007, Ministry of Power, Government of India



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Compliance paths to ECBC 2007 in India64, BEE

Compliance approach to the BEEC plans are currently proposed to follow two optional paths : -the

prescriptive approach and the performance approach. Prescriptive requirements in most codes are

component specific and specify minimum performance criteria for building systems such as building

envelope, HVAC and lighting. Envelope performance criteria vary according to climate zone and

building occupancy type. Building materials and systems are chosen and specified according to the

code requirements. This is a step- by- step path that requires the user to show the compliance of the

design and construction practices towards the list of prescribed requirements. Most prescribed

requirements are associated with a performance characteristic of the building material to be used.

This path does not allow flexibility as all prescriptive requirements must be met if one chooses to

follow it.

A performance based approach in general refers to specifying the annual level of overall energy

consumption (energy budget) in the targeted building and the methodology to calculate the sub

budgets of different energy uses regulated by the energy code, such as space conditioning, lighting,

and service water heating. It is an alternative method to comply with the code. In order to comply with

this method, an hourly energy simulation needs to be performed as per the code. The 'Whole Building

Performance' method is more complex than the 'Prescriptive method', but offers considerable design

flexibility.65

Given that the energy code is a highly technical document and will be primarily used by architects,

engineers, builders and government officials, appropriate training and capacity building of this

stakeholder group to easily understand and use the code should be taken up as a priority.

The BEEC addresses five broad components in the building;

Building envelope

Heating, Ventilation, Air Conditioning

Lighting

Power

Service hot water

As seen from the international review, most codes, as proposed for Bhutan too, consist of the above

five building components to address energy efficiency in the building design and construction. These

components can be monitored for energy efficiency and cover the entire building energy use of the

building.

Building Envelope

The building envelope refers to the exterior

façade, and comprises of opaque components

and fenestration systems. Opaque components

include walls, roofs, slabs on grade (in touch with

the ground), basement walls, and opaque doors.

Fenestration systems include windows, skylights,

ventilators, and doors that are more than one-

half glazed. Envelope design strongly affects the

visual and thermal comfort of the occupants, as

64 Energy Conservation Building Code User Guide, 2009, Bureau of Energy Efficiency, India 65 Energy Conservation Building Code User Guide, 2009Bureau of Energy Efficiency, India



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well as energy consumption in the building, as heat transfer from between the exterior and interior of

the building takes place through the envelope. The code specifies minimum heat transfer values for

roofs walls and fenestration for the different climate zones.

Walls

Heat transfer takes place through walls, windows, and roofs in buildings from higher temperature to

lower temperature in three ways-conduction, convection, and radiation. Conduction is the transfer of

heat by direct contact of particles of matter within a material or materials in physical contact.

Convection is the transfer of heat by the movement of a fluid (air, gas or liquid). Radiation is the

movement of energy and heat through space without relying on conduction through the air or by the

movement of air.

Roof

The heat transfer process involved in the roof, is similar to the heat transfer that takes place in a wall.

Heat transfer across the roof is more prominent compared to the wall because of higher incidence of

solar radiation.

Depending on the properties of the

roof material and construction, the

roof reflects a part of the solar

radiation back to the environment,

and absorbs the other part of the

heat in the roof. Finally, a portion of

the absorbed heat in the roof is

emitted as long-wave radiation back

to the environment and the

remaining part of the absorbed heat

is carried inside the building. This heat transfer process is governed by the 'Solar Reflectance' and

'Emissivity (Thermal Emittance)' properties of the roof material, apart from the thermal conductivity

of the materials used in the roof.

Fenestrations

Heat transfer across glazing products or

fenestration (windows, door, and skylights) is

similar to the heat transfer that takes place

across walls and roofs through conduction and

convection.

In addition, direct solar radiation contributes

to solar heat gain through the fenestration

Key Performance Indicators for building envelopes components such as walls, roofs and insulations

material used are as follows:

Parameters such as U value, R value, thermal resistance,

U-factor for wall materials , roof , insulations (glasswool, thermocol, EPS and XPS, PUF

etc.)– lower the better

Power savings in kWh

Synergy

Application and benefits



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system. The ability to control this heat gain is characterized in terms of SHGC. SHGC is the ratio of the

solar heat gain that passes through the fenestration to the total incident solar radiation that falls on

the fenestration.

Table 26: Key performance indicators for fenestration

Fenestration

Name High performance glass

Parameters Performance of a glass can be measured by rating it on a

scale of 1-5 based upon following parameters :

SHGC ( Solar heat gain coefficient)

U value ( Heat transfer coefficient)

VLT ( Visible light transmission)

Air tightedness

U factor(U factor lower the better) High performance glass : W/m2.deg.k

Normal glass : W/m2.deg k

Power saving WIP

Synergy HVAC

Heating Ventilation and Air Conditioning

Heating, Ventilation and Air Conditioning (HVAC) refers to the equipment, distribution systems, and

terminals that provide, either collectively or individually, the heating, ventilation, or air-conditioning

requirement to a building or a portion of building. HVAC energy use in a commercial building can

increase and decrease significantly depending on how efficiently the combination of air side systems

and central plant operates. This component is not that significant in most of Bhutan given the cold

climate of the region.

The best HVAC design considers all the interrelated building systems while addressing indoor air

quality, thermal comfort, energy consumption, and environmental benefits.

The Code determines the minimum equipment efficiencies for air conditioning systems, chillers and

economizers. It also determines the minimum insulation in the ductwork.

Table 27: Key performance indicators for HVAC

HVAC

Name Energy efficient air conditioning system

Parameters ASHRAE 90.1 2010 has set down parameters for :

EER (Energy Efficiency ratio - heat removal in BTU/h divided by

input in watts)

COP

Application and

benefits

Application

Heating, cooling,

Maintaining desirable humidity and temperature levels,

Improves indoor air quality, increases comfort level of occupants

Helps in achieving proper ventilation

Benefits

An efficient system with proper design, installation and operation

would reduce the air-conditioning load by more than 20 %.

COP As per minimum standards

EER As per minimum standards

Controls Any HVAC system should be temperature controlled and shall be capable of

providing a temperature band as specified in ECBC



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Power saving WIP

Service Water Heating and pumping

BEEC through mandatory requirements seeks to minimize energy usage in water heating systems by

taking the following initiatives:

• Utilizing solar water heating

• Specifying heating equipment efficiency

• Maximizing heat recovery and minimizing electric heating

• Insulating hot water storage tanks and pipelines

• Reducing standby losses

• Reducing heat and evaporation losses in heated swimming pools

For some building types such as large hotels and hospitals service water heating can be a major energy

consumer. Inefficiency in water heating is caused primarily by inefficiency of the heating equipment,

and by heat loss from hot water storage tanks and the distribution piping network.

The code determines minimum efficiencies of hot water systems, minimum insulation in hot water

piping and water pumping systems.

Lighting

Lighting accounts for 15% of total energy consumption in buildings in Bhutan. Lighting is an area that

offers many energy efficiency opportunities in almost any building facility, existing or new.

While energy efficiency is essential for many reasons, lighting designers also need to consider a host of

other factors, including the effect of quality of light on the visual comfort and productivity of the

occupants. Small improvement in lighting quality can improve productivity of the user substantially.

In practice, the right quality and quantity of light can be provided efficiently (with less energy) by

using the right technology and its effective integration with daylight.

The code determines minimum lighting power densities for interior and exterior lighting powered by

electricity. It also mandates the use of lighting controls.

Table 28: Key performance indicators for lighting

Lighting

Name Energy efficient lighting

Parameters Efficacy of lighting technologies

Energy consumption

Life

LPD Any technology in the area of lighting should be able to cater to the area as specified by Code in terms of LPD

CRI Quantitative measure of its ability to reproduce the colors of various objects faithfully in comparison with an ideal or natural light source. Higher the better.

LED lamps have achieved CRI up to 95.

Need to assess the benchmarking

CCT The CCT rating for a lamp is a general "warmth" or "coolness" measure of its appearance. However, opposite to



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the temperature scale, lamps with a CCT rating below 3200 K are usually considered "warm" sources, while those with a CCT above 4000 K are usually considered "cool" in appearance.

Reflector performance WIP

Power saving WIP

Synergy HVAC and lighting loads

Electrical Power

The Building Energy Efficiency Code has only mandatory requirements for the electric power systems

installed in buildings. These provisions are related to distribution transformers, electric motors,

power factor and distribution losses.

It is clarified here that building code in any country requires a detailed market as well as technical

analysis to finalize requirements. This draft code document is a structure for understanding different

stakeholders in Bhutan and requires much detailed work and a legal process before finalized for

Bhutan. The draft code structure is attached at Annexure-L.



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11. Implementation Framework

The process of code development, implementation and enforcement is a rather comprehensive and

collaborative process amongst various stakeholders from the building industry and the government

bodies at central, state and city levels.

Standards and codes are developed at the central government level. Subsequently the central

government advises all the state/ local governments and the stakeholders for their voluntary or

mandatory adoption at the state or local or city levels.

There are several aspects that come into play at the various stages of development, enforcement and

compliance of BEED.

The development of the code document itself is a stakeholder based and consensus driven process. It

is an iterative process with wide stakeholder participation, informed by field surveys and market

assessment of materials technologies and their costs. Technical values are determined by conducting

actual simulations of buildings to determine energy efficiency potential and cost effectiveness of the

code.

After the code document is finalized, there are three aspects to enabling and ensuring compliance with

codes at the state and local government levels.

Adoption: – This is the process of making amendments to the national code and incorporating the

provisions in the local bye-laws and development requirements.

Implementation: - This is the process of designing and constructing buildings to meet the amended

provisions incorporated in the local bye-laws and development requirements.

Enforcement: - This is the process of checking the buildings to ensure that the buildings meet local

bye-laws and development requirements.

Most of these processes have already been undertaken in the development of the building energy code

of Bhutan as is being recommended by way of this document, but a lot of the work still remains to be

done.

The attached flow chart gives a detailed overview of the current status with respect to code

development in Bhutan.

Table 29: Flowchart for different stages of building energy efficiency code for Bhutan



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Ph

as

es

Legal Framework

Code Development Process - Phase 1

Code Development Process - Phase 2

Proposed Stakeholder/ Actor

Output D

EV

EL

OP

ME

NT

- I

nit

ial

Mandate International Review DRE

National Review DRE Local Survey and establishing national trends

Construction Practices DRE Building-vide Energy Baseline

Determination of Climate Zones DRE

Referenced Standards DRE

Stakeholder Identification DRE Fixing roles and responsibilities

Compliance methods and options DRE Simple or Flexible

Develop Code Document DRE Stakeholder Feedback

DE

VE

LO

PM

EN

T -

S

tre

ng

the

nin

g

Bhutan EE&C Act Nodal Agency (TBD) Policy Goals for Buildings Energy Efficiency

Techno-Economic markets assessments for building

materials and technologies

Nodal Agency (TBD) Performance Benchmarks, Availability of materials

established

Whole building performance and life cycle analysis

Nodal Agency Savings potential and cost effectiveness established

Stakeholder Research/ review

Stakeholders Consensus

Public Review of Code Document

Public Refinement

AD

OP

TIO

N Authority having

Jurisdiction at the Centre

Adoption of Code Local Government Incorporating BEEC in Local Bye-laws

IMP

LE

ME

NT

AT

ION

Institutional framework for Code

Implementation

Project Management Unit

Training and Capacity Building

Nodal Agency (TBD), PMU

Greater up-take from the market

Public awareness Nodal Agency (TBD), PMU

Ease of administration

Compliance Forms, Guidebooks, Model Admin.

Procedures for checking compliance and enforcement


Greater up-take and ease of administration

Evaluation of energy savings of Code


Determination of effectiveness of Code

Maintenance of Code Nodal Agency/ PMU

EN

FO

RC

EM

EN

T

Authority having Jurisdiction at the

Centre

Administration and Enforcement of the Code

Local Administrative Authority having

Jurisdiction

Specify building permit rules and regulations


Jurisdiction

Compliance

Development of Enforcement Roadmap


Jurisdiction

Compliance

Pilots and Demonstration Projects

Nodal Agency/ PMU

* Text in red denotes- Actions undertaken during the current study by the Department of Renewable Energy for code development.

Text in green denotes - Proposed future actions.



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11.1. Key actions required for implementation

Developing a building energy code is a rather elaborate process requiring a variety of data and analyses.

As it's been observed in the preceding sections, a lot of preliminary work has already been done for this work.

Even though a code document has been drafted, a lot more effort needs to go into this exercise to make the code

a robust document. The following activities can be distinguished as part of the building energy code

development process:

11.1.1. Policy development

Development of Bhutan Energy Conservation Act or Law, which is the pre-requisite for this kind of

work.

Identify nodal agencies at national as well as local level to speed up code activities

11.1.2. Market assessment

Detailed survey of local buildings: A detailed survey of local buildings to collect information

about the building stock and its energy use and determine typical base case buildings to be used

as benchmarks for developing and evaluating code requirements. Local climate data and information

on the local availability and costs of construction equipment and materials need to be gathered as

well.

Computer based simulations: Technical, energy, and economic analysis, including computer

based simulations applied to base case buildings to estimate energy savings and cost effectiveness

of proposed code requirements. Knowledgeable local designers and contractors are a key source

of professional judgment and should therefore be consulted early on in the building energy code

development and adoption process.

Strengthening the building code: The building energy code should include detailed and objective

documentation (for example, technical data such as equipment ratings or tables of default values),

explicit standard requirements, including compliance forms (that are easy for inspectors to

check), and alternate compliance options. In the case of performance based compliance, a computer

software performance method with specialized compliance software (computer simulations of

building energy use). Provisions for continued building energy code maintenance and regular code

revision and updates should be created.

Public review with key stakeholders: The inclusion of key stakeholders in the code development

process allows issues to be sorted and addressed before the building energy code is finalized. It also

greatly increases the likelihood that the key stakeholders will support the building energy code once it

is adopted and work to see it utilized within their trade or professional organization.

After a public review of the final building energy code draft and inclusion of comments, it would be officially

adopted as a voluntary or mandatory code. Four issues need to be considered for strengthening and finalization

of a building energy code:

1. A decision needs to be made whether the code should emphasize simplicity (and thus easier

application) or provide for flexibility to allow designers and architects to find effective ways to meet

the code requirements. In new code developments that cover all new buildings, often both prescriptive

and performance based compliance paths are introduced, allowing designers to choose. Especially for

smaller, less complex buildings, the simpler prescriptive path is preferred.



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2. The code takes into account the local availability and costs of equipment and materials.

3. The code requirements should be beneficial as a whole. This means that any additional costs of

implementing the necessary measures, plus the costs of any supporting programs are balanced by

energy savings and other benefits over the lifetime of the building, if not less. The code developers

should thus use a life cycle cost (LCC) analysis and specify those measures that have the biggest impact

on energy savings for money spent.

The development and later implementation and enforcement of the building energy code do not take place in an

institutional vacuum. Implementation, enforcement, and the future sustainability of a code will be enhanced if

the following arrangements are put into place during the development stage.

Figure 42: Steps for implementation, enforcement and stability of code

A project unit will manage the development process. The unit should be directly linked to the

government unit or agency in charge of code development.

Consultants will perform various market research and analysis tasks.

The standing committee will have a strong involvement from local experts in the development process.

This includes task forces to tackle specific points.

There can be links with relevant organizations. This can be in the form of a working group of

stakeholders that would review outputs and participate in acting on realistic and relevant

Policy goal for BEEC

Survey local buildings,

benchmarking; survey

construction materials market

Technical, energy economic analysis to

estimate energy savings/cost-

effectiveness of proposed measures

Code document drafting

Development of compliance

forms/procedures, guidebooks,

administrative procedures for checking

compliance

Training and capacity building, public awareness

Evaluation of energysavings and BEEC effectivenss



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recommendations.

There will be a public process for review and integration of comments.

A structure to supervise the implementation process.

An enforcement agency (if mandatory) will be employed.

Formation of a group that can maintain and update the code in the future will be necessary.

For building energy codes that can be actually applied and result in energy savings, the development of the code

must be supported by the build-up of an implementation and, eventually, enforcement infrastructure including

compliance check methods and enforcement roadmaps. Finally, no building code shall be successful without

building capacity throughout the entire building supply chain and amongst architects, engineers, builders and

local government officials. Consumers need to be made aware of the benefits of energy efficiency investments in

buildings.



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12. Policy Instruments -

Recommendations The report has so far provided an overview on various energy efficiency and conservation opportunities in

building sector at Royal Kingdom of Bhutan. The report also mentions the importance of having BEEC

(building energy efficiency code) and how the energy efficiency in existing and upcoming buildings can be

enhanced through implementation of practices prescribed in the code.

However, merely prescribing the best practices in the interest of energy efficiency cannot lead to wider

acceptance in the society. Energy efficiency generally works on a push-pull mechanism. Implementation of

energy efficiency measures on a country wide scale requires a guided support from the government. The

government can introduce policies that improve energy efficiency in the energy intensive sectors. Thereafter the

government can push the implementation of policies through appropriate enforcement measures and can pull

the society through various capacity building initiatives.

Having realised the importance and need of energy efficiency measures in Bhutan, it is recommended that the

energy sector stakeholders (as per the governance structure) shall jointly work and define policies for wider

implementation of energy efficiency measures. This will create an environment favorable for sustained energy

efficiency improvements.

Based on the findings of this study, here are some recommendations on introducing energy efficiency policies

in the country.

Introduction of Energy Conservation Act or Law in Bhutan – Prerequisite.

Launch of Standard & Labeling (S&L) program for equipments and appliances – Will benefit all

building types.

Initiate exercise for implementation of practices prescribed in building code – Long term

phenomenon.

Launch of program for improvement of Bukhari system – Households.

Initiate capacity building programs and strengthen ongoing awareness programs

12.1. Introduction of Energy Conservation (EC) Act in

Bhutan

Enactment of an EC Act in Bhutan is a prerequisite for large scale deployment of energy efficiency measures.

The prime objective under the EC Act is to reduce the energy intensity of the economy. The EC Act can be

referred as a supreme document created under the judicial powers of the country. The act can empower the

government of Bhutan to create a nodal institution that has the responsibility and authority to spearhead

energy efficiency measures in the country.

The Act can be considered as a legal and operational document which empowers the government to develop and

enforce policies so as to channelize large scale implementation of energy efficiency measures. Some of the key

areas (but not limited to) that can be part of the EC Act are given below.

Notify the energy intensive sectors in the country where it is important to introduce energy efficiency

measures.



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Introduce measures and policies to stimulate energy efficiency practices in energy intensive sectors.

Empowers the government to enforce policies in the interest of energy efficiency and conservation.

Prescribe the energy consumption standards for equipments and appliance through introduction of

S&L programs.

Empower the government to regulate the market so as to control the quality of electrical products

entering in Bhutan through imports.

Prescribe practices under building energy efficiency code for efficient use of energy in buildings in the

country.

Empower the government to initiate monitoring and verification activities to check the compliance

under energy efficiency norms and ensure integrity under various energy efficiency and conservation

initiatives.

Promote research & development in the country.

Formulate and facilitate implementation of pilot projects and demonstration project.

Create awareness and disseminate information on energy efficiency policies and measures.

Empowers the government to initiate capacity building programs in the interest of energy efficiency.

Promote opportunities for innovative financing of energy efficiency programs in the country.

Define legal rules and empowers the government to have a tribunal to for energy sector.

The Act will be useful to establish systems and procedures for implementation of energy efficiency and

conservation practices in the country. Taking reference from the powers under the act various policies can be

framed, some of which are shared next.

12.2. Launch of Standard & Labeling (S&L) program

The energy efficiency program in the equipment and appliances sector is globally referred as standards &

labeling (S&L) program.

Energy efficiency labels are informative labels affixed to the products to describe the product’s energy

performance (usually in the form of energy use, rating). These labels give consumer the information

necessary to make informed purchases.

Energy efficiency standards are well defined protocols which are used to obtain a sufficiently accurate

estimate of the energy performance of a product in the way it is typically used, also it target limits on

energy performance based on specified test protocols.

The objective of this program is to provide the consumer an informed choice about the energy saving and

thereby the cost saving potential of the relevant marketed product. Without a credible energy label, a consumer

looking at an appliance has no idea whether a product saves energy or is an energy guzzler. The energy usage

pattern of an appliance is usually not predictable, and invariably not known to the user. Similar to other energy

efficiency programs, energy labeling aims to the market transformation of energy using products and

appliances toward greater energy efficiency.



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The energy labeling programs help consumers to understand which products are most efficient and help them

to choose the more efficient ones. At the same time, they create healthy competition among manufacturers to

produce and market the most energy-efficient models and thus promote efficiency.

In Bhutan, a large portion of demand in appliances sector is met through imports. Considering the context of

Bhutan, since at present there is no energy efficiency qualification criterion for import of appliances there is a

probability for getting imports of cheap and in-efficient products from the neighboring countries. Hence, it is

important for the Royal Government of Bhutan to initiate an energy labeling program for commonly used

products such as lightings, geysers, refrigerator, air conditioners and washing machine or else initiate policy

measures so as to promote import and sale of only energy labeled products (products that have energy label of

other countries).

Based on the findings under this study and discussions with stakeholders and consumers in Bhutan, some S&L

policy options for appliances that can be considered are given below. The approximate saving potential has also

been indicated.

Table 30: Ranking of policy options for standards and labeling of appliances

S. No. S&L program options Consumers targeted Energy saving

potential (%)

1. Lighting* Institutional, commercial and domestic 30-40 %

2. Room heater* Institutional, commercial and domestic 10-20%

3. Water heaters (geyser)* Institutional, commercial and domestic 10-20%

4. Ceiling fan Institutional, commercial and domestic 20-30%

5. Air conditioner Institutional and commercial 20-30%

6. Rice cooker* Domestic and commercial (hotels and hospitals)

7. Refrigerator Domestic and commercial (hotels)

8. Heat pump Commercial and intuitional (new construction)

* indicates - most used appliances in Bhutan.

12.3. Energy Audits for different buildings in Bhutan

Energy audit is a very important exercise to gauge efficiency of energy consuming equipments and appliances in

buildings. Through this exercise, number of standard audit reports have been developed. The government can

decide voluntary or mandatory energy audits of buildings in Bhutan and can direct them to report their actions

to improve energy consumption.

12.4. Implementation of BEEC (Building Energy Efficiency

Code)

Based on the various assessments under this project it has been observed that most of the equipments being

used in buildings such as lights, geysers, rice cookers, refrigerators, ceiling fans and air conditioners are not

energy efficient and therefore needs replacement. Further, the usage of conventional materials, technology and

constructional practices is more dominant in the country and awareness on upcoming energy efficient

technologies, design and constructional requirements is lacking.



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Our understanding suggests that in Bhutan there is a huge potential for saving energy usage in buildings

through replacement of inefficient equipments with efficient ones and also through adoption of energy efficient

constructional practices.

The main components of building that are important from an energy efficiency aspect comprise building

envelope parameters (mainly covers construction practices such as fenestration, wall, roof, ceiling, window and

doors), electrical load (lighting, space heating, water heating, cooling and other load in office & kitchen section).

To make dramatic progress toward low-energy buildings in Bhutan, owners, designers and energy program

managers need prompt and meaningful information on these building and their performance components. The

information about these parameters facilitate in assessing the pattern of energy consumption. Eventually this is

then used to set a baseline of energy consumption and also to identify various probable energy saving

opportunities. The information pertaining to building specific energy efficiency practices is usually covered

under the BEEC.

The BEEC developed under this project comprise information on realistic opportunities to save energy and

GHG emissions from building sector at Bhutan. The BEEC is an important tool to improve energy efficiency in

new and existing buildings. The code set requirements for how energy-efficient a building will be. The code

hence is of utmost importance as it facilities following advantages.

Save consumers money,

Reduce pollution and increase reliability,

Protect consumers and ensure health and safety,

Provide quality and comfort,

Help consumers and builders make a cost effective investment,

Help improve long term sustainability.

It is recommended that the Royal Government of Bhutan shall introduce policies to initiate implementation of

practices prescribed in the code. The implementation of energy efficiency practices in the building sector is a

long term phenomenon and the policies shall target enforcement of EE measures in a phased manner.

12.5. Launch of program for efficiency of Bukhari system

In addition to electric room heaters the people in Bhutan also use firewood based Bukhari system for space

heating. Bukhari is used for burning firewood. It is a kind of wood stove which is found across Bhutan. The

firewood is usually sourced from hardwoods and softwoods depending upon the availability in different regions.

The usage of firewood is dominant in regions falling under alpine and mid-montana climatic zones such as

Bumthang, Trongsa and Thimpu etc.

The energy efficiency improvement in a firewood burning system can be divided in two aspects, following the

best practices while burning the firewood and selection of right stove (Bukhari). These have been explained

below.

To get the most out of firewood as fuel for space heating, it is important to properly dry (season) the wood.

Well-seasoned firewood will start easily and burn bright with little smoke.

Moreover, replacing the conventional wood stove with a more energy efficiently wood stove can save fuel,

money and protect the home occupant’s health. The conventional stoves (locally made) burn wood inefficiently

which wastes firewood, pollutes the air and creates dust inside the home. Newer stoves can reduce smoke and



PwC 83

dust, as well as cut heating expenses. The Unites States Environment Protection Agency (US EPA) has initiated

certification of wood stoves so as to make it energy efficient and more safer for home usage.

The US government has initiated measures to enhance the know-how amongst the people to promote usage of

right kind of wood stoves and its usage in an efficient manner. The basic criterion of limiting the design of wood

stove is the emission level per kg of fuel wood. As per the present norm under US EPA qualified wood-burning

fireplace program the qualification criteria for wood stove is 5.1 g/kg66.

The qualification criteria indicated by the US EPA not only aims to improve the design and safety of wood

stoves but it is also a direct initiative to enhance the energy efficiency of the system by limiting the emission

level of gases such as carbon dioxide, carbon monoxide etc.

As per the US EPA program, following the guidelines pertaining to firewood burning practices and using the

right kind of wood stove can result in approximately 50% more efficient operation of wood stove and can limit

the use of firewood to 1/3 rd for the same heat. This will also result in 70% lesser emission of pollution.

In Bhutan, the usage of wood stoves is quite high in many areas of central and western parts. Introducing

programs for dissemination of information on burning practices and policies for bringing efficient stoves in

market can be very successful in terms of energy efficiency.

12.6. Initiate capacity building programs and strengthen

ongoing awareness programs

Capacity building is an iterative process of knowledge enhancement, learning, application and adjustment.

Realization of the energy efficiency improvement opportunities requires not only the strengthening of technical

and analytical aspects but also the behavioral aspects of building occupants and stakeholders.

The adoption of energy efficient norms in building sector is at a nascent stage and hence the stakeholders need

support for implementation of these opportunities. It is anticipated that transferring knowledge, skills and

know-how about building sector best practices in the field of energy management will be useful in large scale

adoption.

Considering building sector following are some significant capacity building activities that shall be

implemented in order to achieve desired energy efficiency goals.

Develop energy audit agencies in Bhutan

Initiate training programs for trainers (refers to energy sector stakeholders)

66 http://www.epa.gov/burnwise/testmethods.html#fireplace



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- To build their capacity for delivering the program objectives, and,

- Make them capable of imparting training to other stakeholders and consumers down the line.

Initiate training program for retailers and dealers so that they can promote energy efficient

products/materials in the market and can also make consumers aware about the benefits of such

products.

As a knowledge repository, develop standard implementation practices keeping local context in

consideration. The standard implementation practices shall refer to those energy efficiency measures

which can be simply put into practice in the upcoming buildings.

Build the capacity of local stakeholders to organize energy audits for

buildings more frequently.

The awareness building activities also forms a major part of capacity building

programs. Generally where the awareness on energy efficiency is poor the usage

of energy is high. The optimum usage of electrical components and facility has

the potential to bring significant energy savings. However, this requires

behavioural change in the people and facility occupants that can only be

achieved through continuous awareness of towards energy conservation. For

example, it is important to make the building occupants aware about switching

off the equipments when not in use so as to conserve energy.

As indicated earlier, the overall success of energy efficiency initiatives relies on

mass-adoption of measures in the society. Irrespective of the type of energy efficiency policy, implementation of

every policy shall be accompanied by an awareness and outreach campaign to provide information to the

consumers about the potential benefits.

The government should encourage better knowledge of energy efficiency dynamics and make the cost-saving

benefits of new practices and efficient technologies more visible in the public and private sectors. Some key

mediums for awareness and outreach program are shared below:

Information dissemination through print media and website about the benefits of energy efficiency

measures.

Imparting trainings or informative lectures on various subject specific modules designed to improve

performance of buildings.

Conducting workshops in association with policy makers to discuss and deliberate on emerging

technologies and building sector advancements.

Circulation of informative brochures and leaflets during trainings and workshops.

Dissemination of information through a link at the website of Ministry of Economic Affairs.

Sharing of case studies and success stories from implementation of such initiatives in other countries.

Audio and video

media

Print media

Flyer

Brochure

Website

Email



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12.7. Energy efficiency policy requirements

Some of the key requirements pertaining to energy efficiency policies irrespective of the sector are shared

below. The energy efficiency policy will consist of the following aspects:

Strong analytic foundation,

Articulate purpose, goals and objectives,

Incorporate quantitative time-bound targets, both long term and short term,

Identify internal and external factors affecting success,

Be comprehensive and cross-sectoral,

Ensure integration with other national policy areas,

Identify the resources needed to turn strategy into action,

Priorities consuming sectors and policy measures,

Identify actions and assign responsibility,

Provide for results monitoring, updating and revisions,

Facilitate stakeholder engagement and build political consensus.

Several of the above already exist to some degree in energy sector policies in Kingdom of Bhutan and are likely

to need at least a little, if not major, bolstering in the form of technical recommendations to facilitate energy

efficiency policy development and an overall effective functioning.

DISCLAIMER:

This publication has been prepared for general guidance on matters of interest only, and does not constitute

professional advice. You should not act upon the information contained in this publication without obtaining

specific professional advice. No representation or warranty (express or implied) is given as to the accuracy or

completeness of the information contained in this publication, and, to the extent permitted by law,

PricewaterhouseCoopers India Private Ltd., its members, employees and agents do not accept or assume any

liability, responsibility or duty of care for any consequences of you or anyone else acting, or refraining to act, in

reliance on the information contained in this publication or for any decision based on it.

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Documents

Energy Efficiency Study in Building Sector...Energy Efficiency Study in Building Sector 18 January 2014 Prepared for Research & Development Division , Department of Renewable Energy,