Green buildings rating systems in Israel & worldwide - Siano Eran

GREEN BUILDINGS RATING SYSTEMS IN ISRAEL & WORLDWIDE

Student: Eran Siany 028028801

March 2010

Contents

31. Introduction

3 1.1 Research questions/problems

3 1.2 Research goals and methodology

42. Research background

6 2.1 LEED rating system general principles

7 2.2 BREEAM rating system general principles

9 2.3 SI 5281 rating system general principles

11 2.4 CASBEE rating system general principles

173. Rating system comparison

17 3.1 Structure and Weight of categories

19 3.2 Credit Criteria

244. Main Criticisms concerning the rating systems

24 4.1 Insufficient weight for passive heating, cooling & ventilation methods

27 4.2 Energy efficiency assessment method

31 4.3 Credits weight and structure

31 4.4 Setting the bar too low

32

35

5. Conclusions

6. References

2 GREEN BUILDINGS RATING SYSTEMS IN ISRAEL & WORLDWIDE

1.0 Introduction

This research is descriptive-comparative research focusing on four different rating systems for

the assessment of environmental impact of new buildings: LEED (USA), BREEAM (UK)

CASBEE (Japan) and SI 5281 (Israel). The research background outlines the evolution of

green building rating systems following by description of the above rating systems general

principals. Categories weighting and credit structure are then compared and contrasted. In

addition, existing critical literature of the rating systems is reviewed and analyzed, in order to

identify aspects of the rating systems that has not been yet investigated and criticized.

1.1 Research questions/problems

The research focusing on the following main questions:

- Is it possible to create common ground to compare (and conclude) between the following

rating systems: LEED, BREEAM, CASBEE and SI 5281?

- What are the strengths and weaknesses of each of the following rating systems: LEED,

BREEAM, CASBEE and SI 5281?

- What are the main existing approaches to measuring environmental impact of new

buildings?

- Based on the finding established, how SI 5281 could be improved in order to better address

environmental impact assessment of new buildings in Israel?

1.2 Research goals and methodology

The main goals of this research is to reach conclusions regarding the above rating systems

strengths and weaknesses and to provide suggestions to improve the Israeli rating system SI

5281. To that end, I identified the main similarities and deviations between the rating systems

structure, generated charts reflecting the actual category weight at each rating system,

evaluate selected credit characteristics and reviewed existing critical literature concerning the

above rating systems.


2.0 Research Background

In recent years, increasing number of industrial sectors started to recognize the negative

environmental impacts of their activities and to make significant changes to mitigate this

impact. Building design and construction sectors have also begun to acknowledge their

responsibilities to the environment, resulting in an effort to modify the way buildings are

designed, built and operated. A central issue in striving towards reducing environmental

impact of buildings is the need for an applicable standard and/or system for measuring

environmental impact and energy performance.

Worldwide, a variety of rating systems have been developed around the environmental and

energy impacts of buildings. The California Energy Commission developed one of the first

mandatory rating systems, TITLE 24, in 1978. The first voluntary environmental certification

rating system, The Building Research Environmental Assessment Method (BREEAM), was

created in 1990 in the UK (Lowe, 2006). In 1998 the Leadership in Energy and Environmental

Design (LEED) Green Building Rating System was introduced, based quite substantially on

the BREEAM system (Smith, et Al, 2006). In 2005, the Green Building Initiative (GBI)

launched Green Globes by adapting the Canadian version of BREEAM and distributing it in

the U.S. (GBI, 2005). In 2004, The Japan Sustainable Building Consortium (JSBC) launched

the Comprehensive Assessment System for Building Environmental Efficiency (CASBEE),

which is a labeling tool based on the environmental performance of buildings (IBEEC, 2004).

The Cascadia Region Green Building Council, a chapter of the US Green Building Council,

introduced the Living Building Challenge system in the US in 2006 (CRGBC 2006). The Israeli

Standard for Green Building (SI 5281) was introduced by the Standards Institution of Israel in

November 2005. Currently, many of the developed countries have acquired, or in the process

of acquiring, method for the assessment of environmental impact of buildings.

There are two main types of assessment methods of the environmental impact of new

buildings at the design phase: building rating and computer simulation. The rating method

relies on a series of factors/indicators related to the design and the performance issues

together with their defined scales to rate the building’s impact on the environment. The

simulation method uses artificially/virtual settings based on real-world data to assess the

building performance.

Although simulation methods can provide more reliable results than rating methods, using

various conditions in the building lifespan based on objective and subjective settings in

computer programs, there is not a simulation tool for practitioners to conduct a comprehensive

assessment at the present. On the contrary, popular simulation approaches mainly focus on


only one part of building performance such as thermal environment or acoustic environment,

etc. (Chen et al, 2006). It is a challenging and almost utopian task to develop a tool for

complete comprehensive performance simulations of the total environment in and around

buildings. Moreover, during the design phase, designers do not possess yet complete and

sufficient information about the building which required for a comprehensive computer

simulation. In this regard, rating systems have been widely adopted in building performance

assessments, and the simulation method is often integrated in the rating system, mainly to

assess the building’s energy use.

Given their common roots and similar goals, more similarities than differences exist between

the various rating systems mentioned. That said, significant differences in process and

content still remain between rating systems for the assessment of environmental impact of

buildings (Hargreaves, 2005). Fundamental questions exist around the degree to which

content and process differences between systems based on "credit" rating for different design

parameters may influence environmental performance outcomes. Among them: Which credits

should be included in a rating system and which will be ignored? What should be the weight of

a category or a design parameter? How flexible is a rating system structure to adjust to

modification, such as adding or omitting credits?


2.1 LEED rating system

General principles

The Leadership in Energy and Environmental Design (LEED) is a rating system

which grades buildings for their overall environmental performance. The U.S. Green Building

Council (USGBC) developed LEED rating system in 1998. Since its inception, LEED has

undergoing revisions (version 1.0, 2.0, 2.1, 2.2 and 3.0) to address changing environmental

issues and to improve the method of evaluation. The USGBC assessing the building of the

applicant project team, based on LEED guidelines and then rates it. Until now the USGBC has

released LEED for New Construction, Existing Building Operations, Commercial Interiors,

Core and Shells, and Homes. This research will investigate current most updated version of

LEED for New Construction (ver. 3.0).

LEED 2009 (ver. 3.0) certification process assigns points along seven assessment areas:

Sustainable Sites

Water Efficiency

Energy & Atmosphere

Materials & Resources

Indoor Environmental Air Quality

Innovation in design process.

Regional Priority

Under each assessment area there are guidelines addressing environmental concerns, which

the design and construction team should aim to achieve. There is a credit associated with

each guideline and the more the number of credits a building accomplishes, the better it

achieves environmental design objectives. In addition to the elective credits, there are few

guidelines that are mandatory perquisites for all projects.

LEED accreditations are awarded according to the following scale (from low to high):

Certified (40-49 points)

Silver (50-59 points)

Gold (60-79 points)

Platinum (80-110 points).


Categories and weighting method

While majority of the credits are weighted equally in LEED, the different number of

credits which make up each category is in effect the weighting method. The more credits

available in one category, the bigger its weight in the overall calculation. The lack of category

weightings damages the flexibility of the LEED system to adjust and reflect changes in weight

due to construction market changes, environmental priorities, relevant new findings, etc.

2.2 BREEAM rating system

General principles

BREEAM is an environmental rating system mainly applied in the U.K. and to some extent in

the countries in the European Union. It was released in 1990 by Building Research

Establishment Ltd. (BRE) in the U.K. and is the first voluntary rating system for assessing

buildings based on environmental issues (Lowe, 2006). BRE organization was founded in

1921 to initiate advancements and improvements in building environments. It is involved in

certifying and testing the built environment for its quality of space and environmental

consciousness, providing consultancy for the use of new technologies, research in areas

associated with building regulations in the U.K., fire safety issues, structural integrity and

building-occupant interaction. Beginning in 1990, BRE gradually launched separate BREEAM

guidelines for various building typology, which include: offices, retail buildings, industrial

buildings, hospitals, residential buildings, schools, prisons and courts. This research will

investigate current most updated version of BREEAM for Offices (released 2008).

BREEAM Office consists of nine environmental categories:

Management

Health and Wellbeing

Energy

Transport

Water

Materials

Waste

Land Use and Ecology

Pollution.


Assessment credits are awarded for the environmental performance in range of criteria in

each of these categories leading to a category score. The percentage of credits achieved

under each category is then calculated and environmental weighting system is then applied

across the eight category scores in order to determine the final BREEAM rating. The

weighting system applied is the result of a consultation process across a wide range of

professionals and other stakeholders in the UK and is updated from time to time (Seo, 2002).

There are four levels of overall rating:

Pass – 30 to 44 points

Good – 45 to 54 points

Very Good – 55 to 69 points

Excellent –70 to 84 points.

Outstanding – 85 to 100 points.


Similar to LEED, BREEAM rating is based on the number of environmental credits achieved

under each category. However, in BREEAM the number of credits achieved is divided by the

total number of credits available and than multiplied by a weighting factor for each category.

The weighting factors have been derived from a research that was carried out by the BRE to

establish the relevant importance of each environmental credit. Each of the criteria in

BREEAM is usually worth a single credit except where there is a large variation in the

performance of buildings which meet the requirements of the criteria. (For example Reduction

in CO2 Emissions is assigned 15 credits awarded on a scale which runs from one credit for a

building just above the minimum level required to meet UK Building Regulations and up to 15

credits for a building which has net carbon emissions of zero). The score calculation is

described in the example below.


Example of BREEAM score calculation

2.3 Israel Standard for Green Building (SI 5281)

General principles

Israel's green building standard relates to new or renovated residential and office buildings.

The standard is comprised of four chapters: Energy, Water, Land and Other Environmental

Subjects. A building which meets the threshold conditions in each chapter and accumulates

the necessary number of credit points is eligible for “green building” certification. A cumulative

score of 55 - 75 points entitles a building to a “green building” label, while a cumulative score

of more than 75 points allows it to be certified as an “outstanding green building”. During the

course of preparing the energy chapter and in light of the importance of the issue of energy


within the overall framework of green building, it was decided to prepare a standard on the

energy rating of residential buildings (Israel Standard 5282). The standard was approved by

the Standards Institution of Israel in 2005. To comply with the energy chapter of SI 5281, it is

necessary to fulfill some of the requirements of Standard 5282, especially with regard to

insulation and windows.

The Standards Institution of Israel (SII) is a national body responsible for preparation and

publication of Israeli standards and for the quality assurance of goods and services in the

Israeli market by performing lab test and certifications. In 1953 the Israeli parliament enacted

the Standards Law, thereby conferring statutory status on SII, though its position as an

independent body was maintained. The Standards Law, which is under the jurisdiction of the

Ministry of Industry and Trade, describes SII's purpose as that of "standardization and the

assurance, either by prescribing standards or otherwise, of an appropriate level of the quality

of commodities,... to carry out tests of materials, products and installations,... and supervise

the production of commodities." The law grants the Minister of Industry and Trade the sole

authority to determine if adherence to a standard is mandatory or voluntary. Adherence to The

Israel Standard for Green Building (SI 5281) is voluntary.

Prior to formulation of SI 5281, Israel Ministry of the Environmental Protection surveyed green

building standards worldwide in order to examine the possibility of adopting an already

existing standard. During the review period, it was concluded that a new Israeli standard

should be formulated which is based on the worldwide experience. (Israel Ministry of the

Environmental Protection. 2006). In 2001, a report named “Rating Systems for Green Design

and Construction” was done by the Olander Committee for the Israel Ministry of

Environmental Protection. This report provides an overview of overseas rating systems

existing in 2001 and focuses mainly on the provision of general guidelines for an Israeli rating

system framework. The report also deals with the surroundings of buildings (“Green Region”)

which, in their opinion, is not addressed properly by the rating systems they reviewed. The

report did not develop a methodology for comparing between the various systems. Although

the report reviews some of the rating systems components, it does not review all of each

system’s components and does not conclude about the strengths/weaknesses of each

system.


SI 5281 consists of five environmental categories:

Energy

Land

Water, Waste water and Drainage

Other Environmental Subjects

Assessor Impression

There are two levels of overall rating:

"Green Building" Certificate: 55–74 points

Outstanding "Green Building" Certificate: 75–100 points


In SI 5281, as in LEED, the different number of credits which make up each category is in

effect the weighting method. The more credits available in one category, the bigger its weight

in the overall calculation.

2.4 CASBEE General principles

Comprehensive Assessment System for Building Environmental Efficiency (CASBEE) was

launched in 2004 by The Japan Sustainable Building Consortium (JSBC). CASBEE present a

different approach for measuring environmental performance of buildings:

A hypothetical enclosed space bounded by the borders of the building site, as shown in Figure

below, is proposed in making environmental assessments of buildings. The environmental

loadings (L) are defined as "the negative environmental impact that extends outside to the

public environment beyond the hypothetical enclosed space" The improvement of

environmental performance within the hypothetical enclosed space (Q) is defined as "the

improvement in living amenities for building users."


CASBEE - environmental loadings (L) and environmental performance inside building's boundary (Q)


The methodology used to calculate the score is called BEE (Building Environmental

Efficiency) that distinguishes between environmental load reduction (LR) and building quality

performance (Q). All criterions are divided into two groups: Q or LR. Weightings are applied to

each category ( “Q1 - indoor environment”, "Q2 - quality of service", “Q3 - outdoor

environment onsite”, “LR1 - Energy”, “LR2 - Resources & Materials” and "LR3 - Off-site

environment"). In each category there are sub categories such as “Service Ability”, “lighting

and illumination” and “building thermal load” to which another layer of weightings are applied.

Under these sub categories there are individual issues including “noise”, “ventilation” and “use

of recycled materials” to which another layer of weightings applies. A final layer of weightings

is applied to the sub-issues grouped under each of the individual issues. The sub issues

include “ventilation rate”, “CO2 monitoring”, “Adaptability of Floor Plate”, etc.


http://www.ibec.or.jp/CASBEE/english/image/Hypothetical_Boundary_big.jpg�

CASBEE categories and issues are outline below (additional sub-issues not shown):



The scoring criteria for each assessment score are based on the approaches below.

1) Assessment is on a 1 to 5 scale with 3 as the standard score.

2) As a general rule, 1 is earned for satisfying the minimum conditions required by laws,

regulations and other standards of Japan, such as Building Standards Law score 1. And a

building at what is judged to be a general, ordinary level earns 3.

3) The ordinary level (level 3) is a level corresponding to ordinary technical and social

practices at the time of assessment.

The weighting is applies to categories, sub-categories, issues and sub-issues as described.

The total sum of Q credits is calculated (SQ) and the total sum of LR credits is calculated

(SLR).

The final score – BEE, is calculated from SQ and SLR, according to the formula below:

CASBEE Rating Levels:

(S) Excellent BEE=above 3.0

(A) Very Good BEE=1.5~3.0

(B+) Good BEE=1.0~1.5

(B-) Fairy Poor BEE=0.5~1.0

(C) Poor BEE=less than 0.5

All criterions are mandatory in all sections. As mentioned, points are from 1 to 5 while 3 points

considered "standard". (in other words: 3 is zero while 1 & 2 points are negatives)

Since CASBEE credits are applied at each and every individual credit level even if no green

strategy applied (using 3 credits as standard), it addresses the problem in LEED, BREEAM

and SI 5281 that occurs when credits are deemed to be irrelevant to a specific project.

CASBEE presents a totally different approach from the other system compared by dividing its

criteria to Q (building environmental quality) and LR (building environmental load) groups.

Because the Quality score is divided by the Load Reduction score, it is impossible to work out

the correct value of an individual issue before the total score is calculated and this reduces

CASBEE’s value as a design tool (Saunders, 2008).


Example pf CASBEE score spreadsheet (partial):


3.0 RATING SYSTEMS COMPARISON 3.1 Structure and Weights of Categories One of the main questions around the various rating systems is to what extend the credits and

categories of a rating system promotes building with significant reduction in its environment

impact and whether the weighting between the credits reflects their correct weight in achieving

this reduced impact. Each of the rating system attributes a different weighting to the issues

covered. In some the cases these are built into the value of each criterion, in some these are

built into the value of the environmental category, in others the number of credits in a category

is in fact the weightings.

In order to understand the different weight each rating system assign to its categories, the

following pie charts were calculated and generated:

SI 5281 - Categories and Weights

Energy29%

Water, Waste Water & Drainage

17%

Land (Site)19%

Assessor Impression8%

Other Environmental Subjects (waste, construction

management, air quality, ventilation, noise, radiation, transportation and materials)

27%


LEED 2009 - Categories and Weights

Materials & Resources13%

Innovation in Design5%

Regional Priority4%

Indoor Environmental Quality14%

Energy & Atmosphere31%

Water Efficiency9%

Sustainable Sites24%


BREEAM OFFICE 2008 - Categories and Weights

Water6%

Energy18%

Materials13%

Transport8%

Waste8%

Pollution10%

Management12%

Health & Wellbeing15%

Land Use & Ecology10%

It is apparent from above charts that each rating system gives a different weight to each

category. These deviations are required in order to reflect the differences in climate, culture,

building market, etc. between the countries in which the rating system applied to. A good

example for that appears in the Water categories: the Water category weight in Israel's SI

5281 is 17% of the total weight while in LEED the water category weights 9% and in BREEAM

6%. This reflects the lack/shortage in water availability in Israel compared to countries that

enjoy surplus of this natural resource. In the scenarios where significant changes taking place

in the natural resource reserves or where profound modification occur in the building market,

the weight of the rating system categories need to be adjusted in order to reflect these

changes and to address the new priorities in mitigating building impact on the environment.

In LEED, for example, almost every credit equal one point and the category weight is simply

the sum of the number of credits in a category. When the rating system managers wish to add

or delete a credit the whole category weight is modified due to that. Categories and credits

weighting should be perceived as a dynamic tool to reflect various forces and goals such as

natural resources condition, construction market changes, environmental priorities, relevant

new findings, country's norm practice, etc. The weight in the total score should be reevaluated

periodically and be modified per the relevant goals and forced. The Weighing should be

applied at the category level and at the single credit level as well. This will mitigate the cost-

driven credit selection and will allow the rating system steering team to set the bar in right

level at the right time by changing the credits weights as required without changing the all

rating system structure.

3.2 Credits Criteria When examining the credit structure of the above rating systems, a major difference becomes

apparent. LEED, BREEAM and CASBEE specify, for each and every credit:

1. Credit goal and intent

2. Implementation criteria and requirements

3. Submission requirements

4. Calculation methods (if applicable)

5. Examples and resources

The majority of SI 5281 is lacking these specifications and criteria, resulting in cases where

compliance requirements are not clear and subjective. Some significant areas are not

assessed in SI 5281 while addressed in LEED or BREEAM. In some cases, over simplified


criteria is defined by SI 5281 credit. Rating system, by definition, need to provide clear

comprehensive compliance requirement which are not subject to subjective interpretations, in

order to rate all various buildings according to the same standards.

A good case study project to outline the differences in credit criteria between SI 5281 and

LEED is Ramat Hanadiv Visitor Pavilion. The Visitors Pavilion, designed by Ada Karmi

Melamed Architects, is the first building to receive a Green Building standard certificate (SI

5281) from the Standard Institute of Israel and it also received LEED Certified certification.

The Visitors Pavilion has been built as a green mound covered with soil and vegetation. It

houses an assembly hall, a gallery, a lecture hall, education centre and a cafeteria. Three

narrow corridors link the polar sides of the mound. The gallery is located in the middle,

where the two sides meet. Two central axes traverse this building: a longitudinal, scenic axis

linking the nature park and the gardens and a lateral axis encompassing the entrance

square to the gardens and creating an inner courtyard. As light playing a central part in the

architectural plans, natural light penetrates through the upper aperture at the top of the

longitudinal length of the mound.

Visitors Pavilion Site Plan Visitors Pavilion Model

Since Ramat Handiv Visitor Center building was reviewed by two different rating systems

(LEED and SI 5281), it is interesting to compare and identify the deviations. While several

similarities do exists, some differences in credits are apparent:

Heat Island Reduction (Roof) Ramat Hanadiv Visitor Center consist "Green Roof" above almost the entire building. One of

the features of this green mound covered with soil and vegetation is that it reduces heat island


formulation. While LEED rating system provided credit for this, SI 5281 (and BREEAM) not

assessing heat island reduction at all and therefore no credit was granted by SI 5281, as

shown below.

BREEAM credits:

Not assessed.

LEED credits:

(SS credit 7.2) credit awarded where roof finish is light in color. "Green roofs" qualify for this

credit even if 50% of the roof surface is "Green Roof".

SI 5281:

Not assessed.

Light pollution reduction In Ramat Hanadiv Visitor Center the light trespass from the building and the external

illumination was reduced to minimum in order to avoid "Light pollution" that impact night-

active animals. While LEED rating system provided credit for this, SI 5281 (and BREEAM) not

assessing Light Pollution Reduction at all and therefore no credit was granted by SI 5281.

LEED credits:

(SS credit 8) credit awarded when light trespass from building & site is minimized in order to

reduce sky-glow, reduce glare and its impact on night-active animals.

BREEAM credits:

Not assessed.

SI 5281:

Not assessed.

Geothermal air conditioning system A geothermal air conditioning system was installed in Ramat Hanadiv Visitor Center which

uses the fixed temperature of the soil as energy source to cool the building in summer and

heat it during the winter. Pipes deployed underground allowing heat exchange with the soil.

This eliminates the need of air condenser units or cooling towers and therefore saves the

energy these devices uses.

The geothermal air conditioning system main advantages:

- Very high energy efficiency compared to conventional HVAC systems. It Reduces

energy consumption by approx. 30% (and therefore reduces pollution from power

plants)

- Very quite operation

- Long life span (underground pipes last aprox. 50 years)

- No maintenance required.


SI 5281 does not specify criteria pertaining geothermal air condition system. SI 5281 air

condition and heating criteria address only the conventional mechanical HVAC systems. In

LEED, On the other hand, geothermal systems could earn up to 2 credits under EA credit no.

1. However, Ramat Hanadiv Visitor Center did receive credits for the geothermal systems

under the generic Assessor Appraisal Category which can contain any applied green strategy

at the assessor finds to be appropriate. th

Low-emitting materials Only approved low VOC (Volatile organic compounds) Paint, adhesives and sealants were

installed in Ramat Hanadiv, to ensure the high quality of indoor air. As shown below, only

LEED provided credits for this green strategy.

BREEAM credits:

Not assessed.

LEED credits:

ted for provision of low-emitting materials: Adhesives and Sealants, (EQ Credit 4) credits gran

Paints and Coatings, Carpet systems, Composite Wood and Agrifiber Products.

SI 5281

Not assessed.

Additional deviation in credits criteria exists:

SI 5281,

prehensive way to calculate the overall environmental impact of materials. Life-Cycle

is a method of measuring the material resources and energy consumed, and

e environmental impact created by a particular product throughout its life. By comparing

l t the materials and components that

Regional Materials The LCA methodology which included in BREEAM and excluded in LEED and in

offer com

Analysis (LCA)

th

products according to this data, designers could se ec


cause the least environmental damage. Because LEED do not use LCA methodology, it has

ts that aims to encourage more environment friendly materials,

n

several different credi

BREEAM, on the other hand, tackle all of the embodied energy criteria in the LCA section.

LEED’s criteria on this matter appear to be simplistic, for example: the assumption is that the

further the materials travel the greater the impact. However, the difference in impact per tone

between a delivery by road and a delivery by sea is significant and not taking into account i

LEED criteria. SI 5281 not addressing regional materials, as shown below (it gives credit to

Israeli and overseas "green lable materials" regardless of the energy embedded in them).

BREEAM credits:

BREEAM using comprehensive LCA method

LEED credits:

(MR Credit 5.1) credit granted if 10% use of materials extracted and manufactured within 500

miles of the site.

(MR Credit 5.2) credit granted if 20% use of materials extracted and manufactured within 50

miles of the site.

0

SI 5281:

Not assessed.

Natural Light SI 5281 differs from the other system compared here since it takes into account only two

ality of natural light entering a building.

BREEAM are using the Daylight Factor method to estimate the impact of natural

n or measurements. LEED differ from BREEAM since it provides an option to

chieve the credit by using a formula which take into account only the following parameters:

or area, window shape, window height and window visible transmittance.

ces,

he room depth and width and also

nd

parameters: window area and floor area. This appears to be a simplistic way of determining

the amount and qu

LEED and

light in simulatio

a

window area, flo

Since plan shape has enormous effect on distribution of natural light within the interior spa

this formula appears to be insufficient. BREEAM’s formula, which is additional criterion to the

Daylight factor simulation requirement, takes into account t

sky view from desk height.

In conclusion, all rating systems gives, to some extent, attention to quantitative criteria of

natural light but not enough to the qualitative criteria. The qualitative criteria, i.e. glare from

intense light, influence of direct sunlight on interior materials, relationship between depth a

heights of spaces, are hardly taken into account. Some of these issues may be undertake by

the appraisal review notes for the specific project, however, the criteria for these issues are

not clearly defined in the criteria guidelines.


4.0 MAIN CRITICISMS CONCERNING THE RATING SYSTEMS 4.1 Insufficient attention for passive cooling, heating and ventilation methods Use of natural ventilation, daylight and passive cooling/heating methods produces buildings

with low energy use and thus low operating budgets. Daylighting and passive ventilation are

mutually significant part of the architectural design because they defines ceilings heights,

indows sizes & locations, narrow floor plans, atriums, etc. In a well-designed passive

e thermal comfort.

EED provide few credits for natural ventilation, however those credits do not reflect the

e of a

redit

A)

it

to get the significant 10 points for that credit. This is because the Performance

s

half

n

stry

high enough to receive even the basic LEED

ertified level. The main reason for this lies in LEED criteria which aiming to address

w

ventilation space the stack effect and pressure differentials creates th

L

significant weight of passive cooling/heating and ventilation in lowering the energy us

building.

Moreover, there are no credits delegated to architectural schemes that enhance passive

ventilation, i.e. narrow floor plan, atriums, structures that create stack effect and pressure

differentials, etc. (in certain circumstances, credits could be granted under the generic c

section of Innovation in Design). In the paper, "Passive and Low Energy Architecture (PLE

vs Green Architecture (LEED)", Prof. Edna Shaviv indicating that buildings which relay on

passive energy design and has no mechanical systems, cannot score high in LEED EA cred

1 in order

Rating Method is based on appendix G of ASHRAE 90.1-2004, which cannot be used for

buildings without mechanical systems. (Shaviv adds that some credits could be granted to

building with no mechanical HVAC systems by modeling fan systems as “cycling” in the

Proposed Design versus continuously operated fans in the Baseline Design per ASHRAE). In

addition, passive solar energy is not considered as on-site renewable energy and LEED ha

no incentive for passive solar design (Shaviv, 2008). In light of the fact that buildings are

designed to last for a min. of fifty years and that mechanical HVAC systems last less than

of it, this LEED's apparent failure to acknowledge passive energy design importance is eve

harder to understand.

A well-known example emphasizing this issue is the San Francisco Federal building designed

by Morphosis Architects (Thome Mayne) and was completed at the end of February 2007.

The building’s innovative design has been acknowledge by the Federal Government, indu

leaders, local government, professional organizations and academics worldwide, as being a

model for sustainable buildings. The buildings designers applied for LEED Platinum level,

however the buildings did not manage to score

C

mechanical HVAC systems that present less damage to the environment, and do not address

adequately buildings that relay heavily on passive heating and cooling techniques. Many


voices in the building industry calls for revisions in LEED which led to the current LEED v. 3.0

released in 2009. SF federal bldg was revaluated and eventually was granted a Silver level

certification which was still criticized by numerous of professionals who believes the buildin

should receive Platinum level.

g

San Francisco Federal building south facade

The building’s innovative sunscreen is perhaps the most visibly dominant sustainable design

feature. It wraps the south facade to regulate the amount of direct sunshine that enters the

building. The sunscreen absorbs a large portion of the solar energy before it has a chance to

enter occupied spaces and heat them up. In doing so, the screen itself absorbs and then

conducts heat energy into the immediate airspace around it. The heated air rises continually

aust air out of it through computer-controlled

indows.

alongside the building and helps draw exh

w


San Francisco Federal building interior open plan (facing south)

Normally in a building of its size, heat from sunlight that enters through screen walls facades

is a major strain on the building’s cooling system. In this building however, the innovative

sunscreen using that normally burdensome solar energy to create constant hot airflow

alongside the building which helps to pump passively the hot air out of the building during the

day. This not only greatly reduces the cooling load, but also modulates light in the open-plan

office space to the extent that minimal electrical lighting is needed and glare control is

provided. Light sensors detect light levels within the space and computers automatically dim

or brighten the light fixtures, eliminating wasted energy spent on lights that are not needed.

The workstations in the office tower are located right next to the all-window facades, while

executives offices are located in the middle. The floor plan is only about 18 meters wide and

was designed that way to allow natural light to penetrate through the workstations and into the

central offices. This creates a democratization of external views: the executives personnel

accustomed to having the exclusivity a corner-offices or a perimeter one, given up their

traditional locations allowing unobstructed access to natural light and fresh air for all

occupants. Occupants have the ability to open or close windows as needed, giving them direct

control over their microenvironment. The building’s narrow and open plan floors take

advantage of San Francisco’s naturally moderate climate by allowing fresh air to flow through

the entire width of the tower through operable windows. The bare concrete floors and ceilings

absorb the cool air at night and help to maintain thermal comfort during summer days.


San Francisco Federal building 3D computer model

4.2 Criticisms concerning the efficiency of Energy use assessment In order to reach conclusions concerning the relation between LEED predicted energy use

using computer simulation to the actual measured energy performance, Turner, C. and

Frankel, M conducted a research in 2008. According to their paper, LEED energy simulation

turns out to be a good predictor of average building energy performance for the sample they

used. However, there is wide scatter among the individual results that make up the average

energy savings. Some buildings do much better than anticipated, as evidenced by those in

chart below, with measured Energy Use Intensity (EUI) above the diagonal line. On the other

hand, nearly an equal number are doing worse and sometimes much worse than anticipated,

as shown below. Several buildings use even more energy than the code baseline. This

degree of scatter, suggests for improvement in energy use prediction accuracy on an

individual project basis (Turner and Frankel, 2008). Variation in results is likely to come from

a number of sources, including differences in operational practices and schedules, equipment,

construction changes and other issues not anticipated in the energy modeling process.


Measured versus Proposed Energy Savings Percentages

In addition, Turner and Frankel compared LEED buildings Energy Use Intensity (EUI) to the

US National Energy Use Intensity data comes from the Commercial Building Energy

Consumption Survey (CBECS), a US national survey of building energy characteristics

completed every four years by the federal Energy Information Administration. They found that

for all 121 LEED buildings compared, the median measured EUI was 69 KBTU per S.F, which

is 24% below (better than) the CBECS national average for all commercial building stock.

Comparisons by building activity type showed similar relationships: for offices, the most

common building type, LEED EUI averaged 33% below CBECS (Turner and Frankel, 2008).

Chart below shows the median EUI by LEED certification level and the individual measured

EUI for each of the buildings included in their research. (Building types that consisting high-

energy activity such as: labs, data centers and supermarkets were excluded). The interim goal

of Architecture 2030 which is, for office buildings, 50% of the CBECS office average, is also

indicated on this chart. However, in addition to the comparison to CBECS and Architecture

2030 benchmarks, the chart reflects the relationships between building’s energy use and

LEED certifications levels. One may expect that the buildings will be more closely grouped

together in this chart. (i.e. all silver rated buildings will be more or less around their median

measured EUI), instead, the buildings are widely spread. The chart even showing that several

Silver and Gold levels buildings EUI values are well exceeding (worse than) the Certified level

EUI. On the other hand, we can see that the median levels are well correlating with LEED

certification levels. It is significant to note that although energy use is an important section in


LEED, it is not the only section and some buildings may score high in other section resulting in

an overall high certification level (i.e. Gold) but with high EUI building.

EUI (KBTU per S.F per year) for Medium Energy Buildings, with Medians by Rating Level

Another research concerning the same matter conducted by Newsham, G.R. , Mancini, S. and

Birt, B. is outlined in their paper " Do LEED-certified buildings save energy? Yes, but...". They

measured energy use data from 100 LEED certified buildings and reached following key

findings:

• On average, LEED buildings use 18-39% less energy per floor area than

their conventional counterparts.

• However, 28-35% of LEED buildings use more energy than their

conventional counterparts.

• The measured energy performance of LEED buildings has little

correlation with certification level of the building, or the number of energy

credits achieved by the building at design time.

The paper suggest strongly that further work needs to be done to define green building rating

schemes to ensure more consistent success at the individual building level.

Most LEED projects achieve credits (points) in the Energy section. However, since the credits

are elective, excluding three prerequisites, a project can gain LEED certificate without

achieving any credits in the Energy section. This fact may lead to certified buildings with poor

efforts on the energy aspects, as shown in this 42 story 145,000 sq. meters new Goldman


Sachs building at 30 Hudson Street in Jersey City, NJ. The building awarded LEED v. 2/v. 2.1

Certified level. As shown in the score below, no credits achieved in Energy performance

credits. (2 credits out of 17 achieved in the Energy section but they do not concerning the

energy performance. The prerequisites were met as well).

Energy and Atmosphere, 2 of 17 possible points: - EA Prerequisite 1, Fundamental Building Systems

Commissioning

- EA Prerequisite 2, Minimum Energy Performance

- EA Prerequisite 3, CFC Reduction in HVAC&R Equipment

- EA Credit 3, Additional Commissioning

- EA Credit 4, Ozone Depletion

This example and the finding above shows that when

Energy credits are part of the total score, a building might

gain certification without achieving sufficient reduction in

energy use. A cost-driven credit selection will always result

in neglecting the Energy credits since gaining them require

most capital investment. This problem should be address

either by establishing high-bar mandatory Energy perquisites or by separating the Energy

section score from the total one. In addition, since energy legislation exists and rapidly being

modified in the countries the rating system addresses, the Energy criteria in the various rating

system must always exceed the most updated government Energy legislation criteria.

LEED relies heavily on ASHRAE (American Society of Heating, Refrigerating and Air-

Conditioning Engineers) standards in its energy credits. The ASHRAE organization develops

HVAC standards based on examination of various aspects, while the environmental aspect is

only one part of their agenda and certainly not the top-rated one. Since, ASHRAE was not

founded and operates as environmental organization, ASHRAE standards may required some

adjustments in order to provide better results in reducing environmental impact of buildings.

ASHRAE 90.1 is the energy performance baseline used by LEED to define a reference

benchmark. LEED grants credit according to the percentage of improvement from this

benchmark. Although it is generally assumed to deliver buildings with significantly higher

performance than the US national CBECS baseline, the average performance of the code

baseline buildings is close to the average performance of US national building stock (Turner

and Frankel, 2008). LEED reference benchmark (ASHRAE 90.1) is not as aggressive as


anticipated. This suggests a need for more comprehensive analysis of the anticipated energy

performance of the baseline.

4.3 Credit weights and structure Many of LEED credits have equal weight in the final score. However, the construction costs

for achieving each of the credits are not equal. One example for this problem is that LEED

grant one credit for a $1.3 million heat-recovery system that will save about $500,000 in

energy costs per year and grant the same weight of one credit for installing a $400 bicycle

rack. Although the division of credits into 7 categories and the prerequisites criteria mitigate

this effect, it is still causing many developers and owners to choose credits based merely on

construction costs and not based on project relevancy, personal agenda or environmental

impact. (Schendler, A. and Udall, R., 2005). Architect Thom Mayne supports and enhances

this criticism in an interview to Architectural Record on Nov 2007. In this interview he called for

LEED to neglect the credit system and to set BTU and CO2 performance requirements levels

instead, similar in nature to existing mandatory US fire codes or building codes.

In an article for Dallas Morning News on Jan 2008, Daniel Brook, a freelance journalist,

describes an absurd situation where residential project in India that includes 168 parking

spaces car garage designed for a family of 6 (28 to 1 car to person ratio) can receive LEED

certification. Due to LEED’s category and credit structure, only a single point is lost for this

overkill parking capacity and the effect on the total score is minor.

CASBEE's approach mitigate this effect that exists in LEED, BREEAM and SI 5281, since all

criterions are mandatory in all sections. CASBEE's points are from 1 to 5 scale while 3 points

considered "standard". In cases where no green strategy applied at criterion it is still receive

(negative) points (1,2 or 3), so the building's performance for the criterion is always calculated.

4.4 Credits that setting a low bar to cross

Until several years ago, LEED main mission was to introduce green building certification to the

public and to create market transformation (Solomon, 2005). Bob Berkebile, former board

member of USGBC, recalls that the USGBC volunteers: “knew that it was clumsy and limited,

and many wanted to wait until it could be put on more scientific footing, but more wanted to

get something out quickly.” Berkebile continues: “What was shocking was that many agencies

and cities so quickly embraced it as their tool, not realizing that it was not regional, did not do

life-cycle analysis, and was focused on corporate buildings.” (Solomon, 2005). Nowadays,

green has become popular and hip. More and more projects have been registered, and LEED

ratings find their way into marketing brochures distributed by developers, building owners,

architects, and contractors. Accredited professionals proudly add “LEED” to their titles, and


most significantly, numerous federal agencies and state and local governments require some

form of LEED certification.

As LEED became mainstream, many voices are calling for raising the bar of its perquisites

and credits requirements. They argue that LEED CERTIFIED level can be achieved without

too much effort in almost any new building.

5.0 Conclusions

This research compared between most current versions of four different rating systems. The

comparison was at one time point. A different research comparing the rating systems at two or

more time points (i.e. rating system's different versions) is required in order to reach

conclusions regarding a rating system's evolution and tendency. The comparison of four rating

system from four different countries compensate, to some extent, for the lack of additional

comparison in another time point, since the rating systems in the various countries are at

different stages of development. At the same breath, it is clear that since we compared

between the rating systems at only one time point, the conclusions drawn hereafter are

relevant to this time point only. The following are conclusions and suggestions for

improvement of the reviewed rating system, focusing especially on SI 5281.

- Categories and credits weighting must be perceived as a dynamic tool to reflect various

forces and goals such as natural resources condition, construction market changes,

environmental priorities, relevant new findings, country's norm practice, etc.

The weight in the total score should be reevaluated periodically and be modified per the

relevant goals and forces. The Weighing should be applied at the category level and at the

single credit level as well. This will mitigate the cost-driven credit selection and will allow the

rating system steering team to set the bar in right level at the right time by changing the

credits weights without changing the all rating system structure.

- In most of the rating systems toady, designers and owners can choose which credit to tackle

and to apply green strategies on and which credit to ignore (excluding the perquisites). A more

holistic approach will rate the building base on its evaluation in all of the credits in all of the

categories. This could be done similar to CASBEE, where credits are applied at each and

every individual credit level even if no green strategy applied using a 1 to 5 point scale while 3

points considered "standard practice". (in other words: 3 is zero points while 1 & 2 points are

negatives). This addresses the problem in LEED, BREEAM and SI 5281 that occurs when

credits are deemed to be irrelevant to a specific project. However, clear definition in every

credit is required as to what "standard practice" stand for.


- A rating system must specify, for each and every credit:

1. Credit goal and intent

2. Implementation criteria and requirements

3. Submission requirements

4. Calculation methods (if applicable)

5. Examples and resources

Rating system, by definition, need to provide clear comprehensive compliance requirement

which are not subject to subjective interpretations, in order to rate all buildings according to

the same standards. When compliance requirements are not clear and subjective, the rating

system fails to act as a reliable measuring tool. In addition, the criteria defined should lead to

achieving the specified goals and not, as shown in the paper, be oversimplified and lead to

poorly-designed buildings.

- The Energy Use Intensity of a building is a fundamental factor in the assessment of its

impact on the environment. Therefore mandatory "high-bar" energy efficiency perquisites must

be defined. In addition, the energy baseline model should not be part of another system or

body (i.e. ASHRAE) and should be developed by the green building rating system and be

flexible to modification due to construction market state, natural resource, etc.

Another option is not to include the score of the Energy category in the total score and to

calculate it separately using its own scale of reference and taking into account the existing

and ongoing changes in the country's energy legislation. This will eliminate the scenarios

where buildings receiving very high total score level (i.e. LEED platinum or Gold) while doing

the minimum required in the energy section.

- Architectural design providing natural heating/cooling and ventilation is fundamental in

reducing building's energy use and in creating thermal comfort. Many of the rating systems

today addresses and encouraging design that lead to naturally ventilated, cooled and heated

spaces. However, much more weight is provided, by the compared rating systems, for the

provision of environmentally friendly mechanical HVAC systems. While the specifications and

criteria for mechanical HVAC systems is well defined and clear, specifications and criteria for

architectural schemes that enhance passive ventilation, i.e. narrow floor plan, atriums,

structures that create stack effect and pressure differentials, etc. are lacking. A building

relaying only on passive heating/cooling and ventilation cannot score high in the Energy

category due to this underestimated weight given to passive methods and due to the lack of


clarity in the criteria. Giving mechanical HVAC systems a larger weight than passive

heating/cooling methods, must be reversed not only because passive methods consumed

much less energy, but also because mechanical HVAC systems durability is about 25 years

while building's structure and envelop lasts mach more than that.

- Life-Cycle Analysis (LCA) is a method of measuring the material resources and energy

consumed, and the environmental impact created by a particular product throughout its life. By

comparing products according to this data, designers could select the materials and

components that cause the least environmental damage. The LCA methodology offers a more

comprehensive approach than a several credits delectated for environmentally friendly, low

energy embodied and renewable materials like done in LEED rating system. SI 5281 not

using LCA analysis as well (it gives credit to Israeli and overseas "green label materials"

regardless of the energy embedded in them). The LCA method is applied in BREEAM rating

system, forcing designers to verify the LCA value of all building's materials.

- Green buildings rating system evaluating numerous buildings and each building differs from

the other by type, size, location, etc. The rating systems, by definition, need to provide

standardized evaluation of the environmental impact of a building. The fact that a rating

system need to be flexible enough to evaluate a vast groups of buildings may lead to

miscalculations of the environmental impact in some buildings. For example: many Lab

buildings require that no sunlight will enter the lab spaces since it may damage materials in

the labs. These labs are lighted entirely by artificial light. Some spaces in Lab buildings can be

daylighted (i.e. lobby, corridors, etc.) However, LEED require that at least 75% of the spaces

will be daylighted in order to achieve that daylight credit. This cannot be achieved in many

labs since large percentage of the floor area require having no sunlight. BREEAM rating

system, on the other hand, tackle this problem by developing separate BREEAM version for

several building types, which include: offices, retail buildings, industrial buildings, hospitals,

residential buildings, schools, prisons and courts. A rating system developed for a certain

building type and taking into account the building type characteristic, should result in better

assessment of the building's environmental impact.


6.0 REFERENCES

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ועדת אולנדר - מדדים לתכנון ובניה ירוקים לאיכות הסביבה (2001) א.ש.ל. איכות סביבה ואקוסטיקה

לאיכות הסביבההמשרד, ירושלים

Education

Green buildings rating systems in Israel & worldwide - Siano Eran