Energy Efficiency in pre-1945 Historic Dwellings in Dublin City

Built to Last – Energy Efficiency in pre-1945 Historic Dwellings in Dublin City

Dublin City Council research project

Upper Leeson Street Area Residents Association AGM 30 April 2014, Litton Hall

Fergal McGirl – Fergal McGirl Architects

Project team

Consultants

• Joseph Little / Building Life Consultancy

• Fergal McGirl Architects

• Michael Hanratty / IHER Energy Services

Steering Group

• Dublin City Council Heritage Office/Conservation Office

• Dublin City Council Architects Department

• Dept. of Arts, Heritage & the Gaeltacht

• Irish Georgian Society

Funding

• Heritage Council County Heritage Plan Grant Scheme 2013

• Department of Arts Heritage and the Gaeltacht Government Policy

on Architecture Grant Scheme 2013

• Classify pre-1945 Dublin housing stock

• Assess the positive & negative energy attributes of different house types

• Examine appropriate interventions to pre-1945 Dublin dwelling

• Assess the heritage impacts and technical issues of energy upgrade

• Study pre-1945 construction materials



A number of firsts….

Project outputs / structure

Better Building Conference 9 April 2014, Croke Park, Dublin

Whats a U-value?

Single glazed sash windows: Solid brick walls:

Modern walls:Modern double glazing:

4.8 W/m2K 1.1 – 2.1 W/m2K

1.4 W/m2K 0.15 – 0.2 W/m2K

Climate and micro-climates in Dublin

DublinColder & higher RH than Glasgow or London

Rainfall lower than Glasgow

…..but more exposure to SW driving rain

Many Irish dwellings needheating when temperatures are higher butwindspeed is stronger (shoulder seasons)Ref: Paul Overy

Energy use in a three-storey Georgian townhouse(Lennox St. case study house)

Finding the balance between energy conservation and building conservation

Classifications

58 house types identified based on:

• Age

• Construction

• Size

• Architectural features

Classifications – variation in scale

7 retrofit case studies

North Great Georges St.,Dublin 1

Albany Road,Ranelagh (19th c.)

Griffith Ave.,Drumcondra


Whitehall Road,Dublin 14

Belton Park Villas,Donnycarney

Upper Leeson St.,Dublin 2

8 largely unretrofitted case studies (dwellings in largely original condition)

Henrietta St.Dublin 1

Ashfield Ave, Ranelagh

Niall St, Oxmanstown

Irvine Tce, East Wall

Brighton Rd, Rathgar

Lennox St, Portobello

Dingle Rd, Cabra

Ailesbury Gardens, Merrion Gates

Technical Features – Analysis of measured resultsAnalysis of measured results – BER

North Great Georges St.,Dublin 1(protected structure)


Griffith Ave.,Drumcondra

Albany Road,Ranelagh (20th c.)(deep retrofit)

Whitehall Road,Dublin 14

Belton Park Villas,Donnycarney

Upper Leeson Street(protected structure)

D2 –> C2

G–> C1

E1–> C3

G –> C3

G–> A3

F–> D1

D2–> C3

North Great Georges Street case study(protected structure)

D2->C2BER

1.03Heat loss area/floor area

€5300Actual heating costs (551 m2 house)

12%Glazing area/floor area

Prioritising Works


0.48Wall area/total heat loss area

F->D1BER improvement

50%Reduction in actual Kwh usage

Whitehall Road case study

21%Increase in fuel cost!

0.29Wall area/total heat loss area

D2->C3BER improvement

9%Increase in Kwh usage!

Belton Park Villas case study

Upper Leeson Street case study

Upper Leeson Street case study

Upper Leeson Street case study(protected structure)

G->C1BER


67%BER - estimate energy savings

12%Glazing area/floor area

Microgeneration?

Window upgrade

http://www.historic-scotland.gov.uk/technicalpapers

Window upgrade

Window upgrade

Secondary glazing Albert Hall, DCU(U value of 1.89 w/m2k measured at Fitzwilliam Hotel)

Window upgrade

Slim double glazing to existing sashes

Walls - In-situ U-value measurements

1.09 1.19 1.62

Measuring absorption rates of solid walls

Measuring absorption rates of solid walls

Walls - Absorption rates

Old ≠ more absorbentAbsorption rate of Dolphin House 1960s brick highest of all samples

X 200Possible variation in absorption rates between brick & rendered wall

X 3Absorption rates of different bricks

Walls – insulation approaches

Calcium silicate board

Floors – insulation from underfloor voids

Roofs – the difficult areas!

• Understand the specific thermal characteristics of your house

• Be aware of the order of priority of works

• Increased thermal comfort is possible

• Don’t expect a significant payback on investment (after attic insulation & heating system upgrade)

• Consult with local authority conservation officer



Approaching an energy retrofit of a traditional house – Some thoughts

30 April 2014, Litton HallUpper Leeson Street Area Residents Association AGM

Environment

Energy Efficiency in pre-1945 Historic Dwellings in Dublin City