Back to Top

 Skip navigation

Extra information
Methodology Previous Releases
International comparison:
See also:
YouTube Video
For more information on this release:
E-mail: environment@cso.ie Berna Lawlor (+353) 1 4984210 Sheona Gilsenan (+353) 1 4984202
For general information on CSO statistics:
information@cso.ie (+353) 21 453 5000 On-line ISSN 2009-7441
CSO statistical release, , 11am

Domestic Building Energy Ratings

Quarter 1 2015

% of row
Period of constructionEnergy rating
ABCDEF-G
1700-19770318252033
1978-1999043837147
2000-200408572483
2005-2009137481131
2010-201536575100

36% of dwellings built in 2010-2015 have an A Energy Rating

Domestic Building Energy Ratings Quarter 1 2015 Figure 1
go to full release

 

In the first quarter of 2015 a total of 21,953 Building Energy Rating (BER) audits were conducted on dwellings, bringing the cumulative total of BER audits conducted since January 2009 to 566,574 (see Table 1). The energy audits shows that 36% of recently constructed (2010-2015) dwellings had an A energy rating while a further 57% of recently constructed dwellings had a B energy rating (See Table 2).

  • Analysis of Table 2 shows that 4 out of every 5 dwellings that had a BER audit in Quarter 1 2015 were constructed prior to 2005; of these just 39% were found to have an energy rating of C or better (i.e. A or B or C).  Meanwhile for dwellings constructed in 2005 or later 86% had an energy rating of C or better.
  • Table 4 shows that 32% of dwellings constructed in Cork county had a rating of C1 or better, this was the highest percentage among all counties with a C1 or better rating. Next among this group was Dublin County with 30% of dwellings having an energy rating of C1 or better. Wicklow was in the middle of this group of counties with an energy rating of C1 or better with 22%.
  • Table 8 describes how the type of space heating fuel used in dwellings covered by the BER audit varied across counties. The three counties with the highest percentage of solid fuel usage were Offaly (24%), Laois (15%) and Westmeath (15%). Solid fuel was the main space heating fuel type in just 6% of BER audited dwelling country-wide.
  • Table 14 compares the oldest and most recent BER rating on a percentage basis for dwellings that have been rated at least twice. Among these dwelling 17% showed no change in their energy rating from their first to their latest BER audit. Also, for the 70% of dwellings that has a D1 or poorer (D1, D2, E1, E2, F, G) energy rating on their first BER audit, 47% (or 33% of the total) had an improved rating of C3 or better on their latest BER audit. This analysis is based on 32,355 dwellings.
  • Table 15 examines the representativeness of dwellings that have a BER audit carried out in Quarter 1 2015. The data were weighted up to national level using Census of Population 2011 figures. The weighted results show that 54% of dwellings had a BER of D1 or poorer, compared with 50% of dwellings in the quarterly BER data. This indicates that a higher proportion of apartments and new dwellings have had an energy audit. A weighted version of other tables provided in this release can be made available by CSO on request.
EarliestLatest
A00
B111
B214
B3412
C1717
C2816
C31114
D11313
D21410
E1105
E293
F103
G142
National DataBER database
A11
B111
B223
B367
C11011
C21213
C31313
D11414
D21212
E177
E265
F65
G97
Table 1 Domestic Building Energy Ratings Certificates 1
number
Period2009201020112012201320142015Total
January4,0974,6668,5596,5226,9677,0006,66644,477
February6,3215,6119,0186,2938,5227,5337,85151,149
March8,7656,1518,9346,5058,2048,3777,43654,372
April8,0305,4837,7774,4388,2948,733 42,755
May7,9215,4788,8675,8718,6468,728 45,511
June8,7285,7327,4594,8647,2618,217 42,261
July8,7725,9767,2535,5357,0979,393 44,026
August7,2726,4577,5315,0506,9738,163 41,446
September7,5187,4258,8764,9768,2779,914 46,986
October6,5988,4069,5736,6898,98410,776 51,026
November6,98111,6199,6278,8299,61010,915 57,581
December6,3528,0439,4846,3706,9457,790 44,984
         
Total87,35581,047102,95871,94295,780105,53921,953566,574
         
1 Includes all Certificates for Dwellings
Table 2 BER Ratings by Period of Construction
% of row
Period of ConstructionEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
1700-18990012234710910153813,422
1900-19290012234711910143827,495
1930-19490012456913910142625,904
1950-1966001246812141111131840,326
1967-19770012691216171199854,177
1978-198200138121519181065437,657
1983-19930013812152019964361,161
1994-19990014914192015754265,668
2000-20040017152121159532197,044
2005-20091411222216964211099,288
2010-201536321693211000008,769
               
Total113711131314127557530,911
               
Table 3 BER Ratings by Type of Dwelling
% of row
Dwelling TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Apartment1291312810111166574,272
Ground-floor apartment01381010911141187731,038
Mid-floor apartment151112111212129533338,896
Top-floor apartment0149988121510761031,989
Basement Dwelling  125265613111139127
Maisonette0281113109101474575,260
House02391214141311544839,143
Detached house112711131414126559134,146
Semi-detached house111510141616137655134,459
End of terrace house11251013131312777936,976
Mid-terrace house11381213111212866874,605
               
Total113711131314127557530,911
               
Table 4 BER Ratings by County
% of row
CountyEnergy Rating Average age
AB1B2B3C1C2C3D1D2E1E2FGTotal
Carlow0127121414151165577,54628
Dublin 01-2412579101113138777117,50335
Dublin County33581113131311655536,82527
Kildare11381214151512644519,42523
Kilkenny0127121313141275599,08233
Laois012910141412966698,16729
Longford0127111212151176794,88125
Louth12481315141310644613,68330
Meath11391416151310543515,04724
Offaly0124812131112989126,94134
Westmeath01381012141411656109,97128
Wexford0125914151513855817,96026
Wicklow11371012131312766914,67631
Clare00161014151413865815,87230
Cork City11481112121312866810,66842
Cork County124111414121110544750,00531
Kerry01371113141412755718,31127
Limerick City0113111415151575678,65935
Limerick County00161113151514755718,54530
Tipperary01159121314138671118,64237
Waterford City012491215181575565,26134
Waterford County0126111314161475569,29732
Galway City012481216181595557,07824
Galway County01261114151412765824,97926
Leitrim00261214121211667123,86629
Mayo01258141514137561014,40429
Roscommon00161113151211656126,00830
Sligo112791112141396699,11029
Cavan013914161312965587,67725
Donegal01261415141311645815,32326
Monaghan0138121112151475575,49933
                
Total113711131314127557530,91130
                
Table 5 BER Ratings by Dublin Postal District
% of row
CountyEnergy Rating Average age
AB1B2B3C1C2C3D1D2E1E2FGTotal
Dublin 103679911121496675,34027
Dublin 2147681011121296673,08034
Dublin 310257791113101011155,11853
Dublin 401479910141498886,86241
Dublin 50024681117151110974,60642
Dublin 61235667111310910175,48655
Dublin 6W112688913148910102,72448
Dublin 700125881214101012176,85154
Dublin 803697781112988118,58741
Dublin 9103689912141091096,00644
Dublin 10  25151512101176782,14441
Dublin 1112912121111111065656,76028
Dublin 1201345681214101113135,23350
Dublin 1321412111211131276543,65429
Dublin 14125899101314108875,46938
Dublin 15125101315151612532111,64317
Dublin 161159101212161585434,77827
Dublin 17 18915201514842213,13924
Dublin 18281215151299932216,06416
Dublin 20 59117781213117541,35629
Dublin 220014813141820107433,85625
Dublin 241125121514161496528,74720
                
Total12579101113138777117,50335
                
Table 6 BER Ratings by Main Space Heating Fuel
% of row
Fuel TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Mains Gas1251115151413105443201,626
Bulk LPG126172118139632117,772
Bottled LPG0137121412121544510702
Heating Oil012612151616126555207,758
Electricity11113581318131091876,563
Coal  00011314141418363,176
Smokeless Fuel   0001315181315342,830
Peat 0  011310111416431,243
Wood Pellets & Chips2715241313105421221,025
Wood Logs2222323813991133521
Solid Multi-Fuel 0000127141413153320,856
               
Total113711131314127657524,072
               
Table 7 BER Ratings by Main Water Heating Fuel
% of row
Fuel TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Mains Gas1251115151413105442200,276
Bulk LPG126172118139632117,720
Bottled LPG013813141411155449735
Heating Oil012612151616126555206,198
Electricity11113581317131092080,630
Coal0001112515151518283,063
Smokeless Fuel   0001417201416262,623
Peat   0011411121417401,277
Wood Pellets & Chips2715231313105422211,032
Wood Logs21233351013991129474
Solid Multi-Fuel00000128141514162920,044
               
Total113711131314127657524,072
               
Table 8 Main Space Heating Fuel by County
% of row
CountyFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
Carlow36479627,539
Dublin 01-247262110113,449
Dublin County7712101036,055
Kildare4639103119,323
Kilkenny30528929,057
Laois304681518,152
Longford261191434,818
Louth553653113,544
Meath424583115,040
Offaly95692416,835
Westmeath1653141539,928
Wexford1691413317,864
Wicklow434296114,593
Clare11611412315,843
Cork City7010182010,543
Cork County4240134249,672
Kerry166199518,226
Limerick City561920408,528
Limerick County2848149118,465
Tipperary1366811118,579
Waterford City611421405,252
Waterford County265213829,258
Galway City174237327,005
Galway County767167324,910
Leitrim067151263,864
Mayo372138314,372
Roscommon37410936,007
Sligo26123959,094
Cavan96910857,609
Donegal08186515,186
Monaghan9747835,462
       
Total38401562524,072
       
Table 9 Main Space Heating Fuel by Period of Construction
% of row
Period of ConstructionFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
1700-189930382210113,058
1900-192931391910127,091
1930-19494238910125,860
1950-1966454267140,200
1967-1977375147153,780
1978-1982345348137,494
1983-19933247118260,755
1994-19993239235165,220
2000-20043837204296,417
2005-20094828192496,113
2010-2015582514138,084
       
Total38401562524,072
       
Table 10 Main Space Heating Fuel by Type of Dwelling
% of row
Dwelling TypeFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
Apartment43550124,014
Ground-floor apartment487431229,691
Mid-floor apartment401581135,923
Top-floor apartment422531230,511
Basement Dwelling299612 117
Maisonette53736235,186
House187045339,123
Detached house1572462134,067
Semi-detached house4641481134,283
End of terrace house582587136,838
Mid-terrace house602397174,319
       
Total38401562524,072
       
Table 11 Average Floor Area by Period of Construction and Type of Dwelling
m2
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-18996953455555105148157143115105117
1900-19296350445242871191231209590100
1930-1949525845505277110119109848197
1950-19667063535556621161251128786103
1967-19776665595562591321391078483109
1978-19826463645410068137142968382109
1983-1993585756584571146150948280109
1994-19996763586759771521611018383110
2000-20047570707770901651771039591115
2005-200981727278909616819110710198110
2010-20158477737586101193212121117111140
             
All7566667054861471551049088109
             
Table 12 Average Primary Energy Use by Period of Construction and Type of Dwelling
kWh/m2/year
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-1899436424393492400463417412394423372406
1900-1929472433417512392448415421394429385412
1930-1949367355289424485461379402344382336367
1950-1966420338312409491302341356314347309332
1967-1977388325283387401327292298286283260289
1978-1982331294248300309310246252260246226251
1983-1993342311258305280284229233250252231242
1994-1999283287243289248263208209234259234227
2000-2004253248210248324221189193216224198207
2005-2009170190161193243164152163175171157168
2010-201520410886113132881029683868193
             
All229255200261366232234245247269259246
             
Table 13 Average Carbon Dioxide Emissions by Period of Construction and Type of Dwelling
kgCO2/m2/year
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-18991029787112851091071069610187100
1900-19291129993115861081071109510390102
1930-1949858062941071109710481897889
1950-196610075678910664869072797079
1967-1977937260849875747467666169
1978-1982806753667773626362575261
1983-1993827158696265575859595358
1994-1999666555655859515154605354
2000-2004585547547248464751504448
2005-2009374034415334363941373438
2010-2015462217233018242217171620
             
All525644578051586158625959
             
Table 14 Dwellings with Multiple BER Ratings
% of total
Earliest YearLatest YearTotal
A2A3B1B2B3C1C2C3D1D2E1E2FG
A1    0         0
A20         0   0
A3 0000         0
B1 0000000 0    1
B2  001000000 0 1
B3 00111000000  4
C1 00023100000007
C2  0013210000008
C3 000123210000011
D1  00123321000013
D20000122232100014
E1 000111122100010
E2000011111211009
F 000111111111010
G0001111112111214
                
Total00141217161413105332100
                
Table 15 BER Ratings Weighted to National Level
% of row
Dwelling TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Apartment126910101011128669163,077
Detached house1127101213131265611675,399
Semi-detached house11149131516138666434,095
Terraced house1126101211121287811262,265
               
Total1126101213141276691,534,837
               

Background Notes

Domestic Building Energy Ratings

 

Introduction 

A Building Energy Rating (BER) is an indication of the energy performance of a dwelling (represented in units of kWh/m2/annum). Actual energy performance will depend on how the occupants operate the dwelling. A BER is based on the characteristics of major components of the dwelling including: wall, roof and floor dimensions; window and door sizes and orientations, as well as the construction type and insulation, ventilation and air tightness features; the system for heat supply (including renewable energy), distribution, and control; and the type of lighting. The BER certificate indicates the annual primary energy usage and carbon dioxide emissions associated with the provision of space heating, water heating, ventilation, lighting, and associated pumps and fans. The energy use is calculated on the basis of a notional family with a standard pattern of occupancy - hence data in this release giving average primary energy use or carbon dioxide emissions are not based on actual data. A BER only covers electricity used for heating, lighting and ventilation with associated pumps and fans i.e. cooking, refrigeration, laundry and other appliance use is not included.

 Since 1st January 2009, a BER certificate and advisory report is compulsory for all homes being sold or offered for rent. A BER is also required for new dwellings that apply for planning permission on or after 1st January 2007. A BER certificate is required to avail of the grants for energy-efficiency improvements to the home that are provided under the Better Energy Homes scheme. 

Access to Microdata 

Further information on the BER scheme (including links to a microdata research tool) is available on the Sustainable Energy Authority of Ireland website at http://www.seai.ie/BER/ 

Revisions 

The figures will be updated on a quarterly basis. While the changes to previous quarters will mainly relate to the most recent quarter, previous periods are also subject to revision.

Coverage 

There are three types of BER Certificates. A New Dwelling – Provisional BER is required for a dwelling that is not yet built but is offered for sale off the plans. A New Dwelling – Final BER is required for a newly-built dwelling before it is occupied. This certificate is based on data collected in a site survey carried out by a registered BER Assessor as well as drawings and specifications for the completed dwelling. An Existing Dwelling BER is required for any existing dwelling that is offered for sale or to let. An existing dwelling is one that has previously been sold or occupied. This is based on data collected in a site survey carried out by a registered BER Assessor. Both the New Dwelling – Final BER and the Existing Dwelling BER certificates are valid for 10 years from the date of issue. They become invalid if material changes are made to the dwelling during that period. This release is an analysis of Final and Existing BER certificates. To ensure that all tables are consistent with each other, records that contain missing data in any of the main classification variables used in this release have been excluded e.g. missing response for county. Records with only the main space heating fuel or main water heating fuel information missing have been included except in tables using those variables.

National representativeness 

BERs are conducted for around 90,000 domestic dwellings each year. Hence there were 566,000 unique domestic BERs (one per dwelling) completed in the period 2009 to the end of March 2015. This compares with around 1.66 million private households enumerated in the 2011 Census of Population. The 2011 Census of Population included questions on county of location of the dwelling, the period when the dwelling was built, and the type of dwelling. These questions can be used to weight the BER data to national level. Table 15 presents an initial weighting of BERs up to national level using the 2011 Census of Population. The weights were calculated by dividing the number of households in the Census by the number of unique BER households. In cases where a household had more than one BER carried out in the period 2009-2015 only the most recent BER was used. Around 7% of Census households were excluded because there were no BER households in the particular stratum e.g. detached houses in Dublin 1 that were constructed in the period 1919-1945. A stratum was classified as a unique combination of County (52 categories - Dublin postal districts were distinguished), period of construction (nine categories) and dwelling type (4 categories). The BER contains more disaggregated dwelling types, e.g. mid-terrace house, but these had to be aggregated to correspond to the Census classification.

In 2015 both the Census and BER files will be retrospectively post-coded. This will make it possible to match both files at household level as postcodes will be unique at letter-box level. This will create an opportunity to calculate weights in a more precise manner.

Non-domestic Buildings 

Since 1st July 2008, a BER Certificate is required for all new non-residential buildings and from 1st January 2009 for all public service buildings and for existing non-residential buildings. The CSO is in the process of obtaining access to the non-residential file.

Definitions 

The BER rating scale is divided into categories from G (largest primary energy usage) to an A1 rating (lowest primary energy usage). The kilowatt-hour is the unit of energy used in Dwelling Energy Assessment Procedure (DEAP). The BER is measured in kWh per square metre of floor area of the dwelling per year (kWh/m2/year). The full range of categories is described in Table A. For the purposes of this release A1, A2, and A3 have been combined together because of the small number of Certificates in these categories.

Table A: Building Energy Rating Categories 

Category

kWh/m2/year

A1

≤ 25

A2

> 25

A3

> 50

B1

> 75

B2

> 100

B3

> 125

C1

> 150

C2

> 175

C3

> 200

D1

> 225

D2

> 260

E1

> 300

E2

> 340

F

> 380

G

> 450

 

County is where the dwelling is located. 

Type of dwelling is selected from one of the following: Detached house; Semi-detached house; End of Terrace house; Mid-terrace house; Ground-floor apartment; Mid-floor apartment; Top-floor apartment; Basement apartment; and Maisonette. 

Year of construction is when the dwelling was originally built. 

The fuel used by the Main Space Heating system. The main space heating system heats the largest proportion of the dwelling. This proportion is calculated using a count of the habitable rooms. It often provides hot water as well as space heating. 

The fuel used by the Main Water Heating system. This category has similar fuel response options to the Main Space Heating system. 

The Total Internal Floor Area of the dwelling is the total area of exposed and semi-exposed floors. It excludes any unheated areas that are thermally separated from the dwelling. The total energy usage is divided by the dwelling floor area to determine the Building Energy Rating.

Table Notes 

Table 1 presents the number of Final and Existing BERs published by month since January 2009. A household that has had BERs conducted in different years is included in each year. This table gives an overview of the number of BER assessments being performed and will inform the user of changes since the previous quarterly analysis. 

Tables 2-11 only include the latest BER published for each dwelling from January 2009 to March 2015; hence the total number of BER certificates is lower than the total in Table 1.

Table 2 shows the general impact of the age of the dwelling on the BER profile. It can be linked with changes to the Building Regulations that require new homes to be more energy efficient. 

Table 3 shows how the BER profile varies by type of dwelling. 

Tables 4-5 profile BERs by county and Dublin postal district. Table 4 is in county within province order. 

Tables 6-7 profile BERs by main space and water heating fuels respectively. Records with a missing response for main space heating fuel have been excluded from Table 6,8,9 and 10. Similarly records with a missing response for main water heating fuel have been excluded from Table 7. 

Table 8 cross-classifies county by main space heating fuel. Mains gas is not generally available in some counties. Some counties use local heating fuels such as peat e.g. County Offaly. 

Tables 9-10 cross-classify main space heating fuel by period of construction and dwelling type. 

Tables 11-13 cross-classify the BER by period of construction and the dwelling type. The latter is more precisely defined in recent years but in the earlier years more general descriptions such as House were in use. It is not possible to reclassify these to detached, semi-detached, end-of-terrace, or mid-terraced house. The average primary energy use and average carbon dioxide figures are notional figures based on assumed energy use factors and occupancy. 

Table 14 is an analysis of properties that had BER audits carried out in more than one year. The earliest and latest BER ratings are cross-classified to show trends in energy savings arising from insulation retrofitting etc. 

Table 15 is an analysis of BER properties after they have been weighted to Census 2011 level. It can be compared with the national profile in Table 2. See the entry under National representativeness for more details.

upArrowHide Background Notes