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For more information on this release:
E-mail: environment@cso.ie Berna Lawlor (+353) 1 4984210 Stephen Treacy (+353) 1 4984076
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 3 2014

     % of row
Period of constructionEnergy rating
ABCDEF-G
1700-19770318262033
1978-1999043837147
2000-200408582483
2005-2009138471031
2010-201429646100

29% of dwellings built in 2010-2014 have an A Energy Rating

Small Graph used for Figure 1
go to full release

Over half a million dwellings (515,732) had a Building Energy Rating audit conducted between January 2009 and September 2014 (see Table 1). The energy audits show that considerable changes have occurred in the characteristics of recently built housing stock and that the type and age of dwelling are the key determinants of energy efficiency.

  • Table 2 shows that a BER rating of A was given to 29% and a rating of B to 64% of audited dwellings that were constructed during 2010-2014. This is a huge improvement compared with the energy performance of dwellings constructed in 2005-2009 where only 1% received an A rating and 38% a B rating.
  • Table 3 shows that mid-floor apartments have the highest BER ratings with 30% awarded an A or B rating. In contrast only 11% of detached houses received an A or B rating.
  • Table 4 shows that 18% of audited dwellings in Dublin County had a rating of A or B compared with a national average of 12%. In Dublin 18, 37% of audited dwellings had an A or B rating compared with only 4% in Dublin 7. This is largely due to Dublin 18 having a high proportion of new apartments.
This map is © Ordnance Survey Ireland. All rights reserved. License number 01/05/001.
  • Table 8 shows how the main space heating fuel varied across counties. The areas with the highest usage of mains gas were the Dublin postal districts (72%) and Dublin County (77%). Mains gas was used in 38% of BER rated dwellings compared with heating oil in 40% and electricity in 15%.
  • Table 9 shows that mains gas was the main space heating fuel in 57% of dwellings constructed during 2010-2014. This proportion increased from 32% for audited dwellings constructed during 1994-1999. In contrast the share accounted for by heating oil has halved from 54% for 1978-1982 dwellings to 27% for 2010-2014 dwellings. Terraced houses had the highest rates of usage of mains gas for main space heating: 59% of mid-terrace and 58% of end-of-terrace houses used mains gas.
  • Table 11 shows the average floor area by construction period and dwelling type. The average floor area of detached houses built during 2010-2014 was 215 square metres compared with 191 square metres for 2005-2009. The average floor area of ground floor apartments built during 2010-2014 was 76 square metres.
  • Table 14 examines a subset of dwellings that had at least two BER audits. Comparing the oldest and the most recent ratings gives an indication of the improvements being achieved through energy efficiency upgrades. Only 5% of the older ratings were classified as A or B whereas this increased to 17% for the most recent BERs conducted on the same dwellings. This analysis is based on 26,625 dwellings.
  • Table 15 examines the representativeness of dwellings that have a BER rating. The data were weighted up to national level using Census of Population 2011 figures. The national level data shows that 9% of dwellings have a rating of A or B compared with 12% of dwellings in the actual BER data indicating that a higher proportion of apartments and new dwellings have had an energy audit. A weighted version of the other tables in this release can be made available by CSO on request.
EarliestLatest
A00
B111
B214
B3312
C1617
C2816
C31114
D11313
D21410
E1105
E293
F103
G142
National DataBER database
A01
B111
B223
B367
C11011
C21213
C31313
D11414
D21212
E177
E265
F65
G97
Table 1 Domestic Building Energy Ratings Certificates 1  
       number
Period200920102011201220132014Total
January4,0974,6658,5576,5196,9667,05337,857
February6,3215,5989,0186,2928,5207,62443,373
March8,7636,1528,9336,5038,2028,43546,988
April8,0295,4817,7744,4388,2938,79842,813
May7,9215,4898,8665,8688,6468,79145,581
June8,7285,7307,4584,8657,2608,28242,323
July8,7725,9757,2535,5357,0939,43944,067
August7,2716,4567,5335,0506,9758,22041,505
September7,5207,4258,8784,9778,27810,00747,085
October6,5988,4089,5756,6898,988 40,258
November6,98111,6239,6278,8349,611 46,676
December6,3548,0459,4876,3726,948 37,206
        
Total87,35581,047102,95971,94295,78076,649515,732
        
1 Includes all Certificates for Dwellings
Table 2 BER Ratings by Period of Construction       
              % of row
Period of ConstructionEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
1700-18990011234610910143812,306
1900-19290012234711910143825,140
1930-19490012456913910142623,903
1950-1966001246812141111131837,405
1967-19770012681216171199849,829
1978-198200138121519181065434,291
1983-19930013812152019955355,660
1994-19990014914192015754260,210
2000-20040017152121159532188,406
2005-20091412222216964211091,858
2010-2014293618103211100007,283
               
Total113711131314127557486,291
               
        
Table 3 BER Ratings by Type of Dwelling       
              % of row
Dwelling TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Apartment1291312811111166574,311
Ground-floor apartment01481010911141197728,327
Mid-floor apartment151212111212129533335,711
Top-floor apartment01491088121510761029,150
Basement Dwelling  12437571410939115
Maisonette128111398101474574,645
House02391214141311544839,485
Detached house112711131414126559122,800
Semi-detached house011510141616137655121,809
End of terrace house112510121213128781032,955
Mid-terrace house11381212121212866866,983
               
Total113711131314127557486,291
               
        
Table 4 BER Ratings by County
 % of row
CountyEnergy Rating Average age
AB1B2B3C1C2C3D1D2E1E2FGTotal
Carlow0126121414151275576,94428
Dublin 01-2402589101113138777106,29735
Dublin County23581113131312655533,95627
Kildare11381213151512644517,66023
Kilkenny0127121313141375598,35433
Laois012910141413965697,37529
Longford0128111211151176794,31825
Louth12481315141310644612,36930
Meath02391416151310543513,62024
Offaly0114812131112889126,26234
Westmeath01381012141411656109,16028
Wexford0125914161512855816,13327
Wicklow11371012131312866913,74231
Clare00161014151412865814,88230
Cork City1148101111131286698,82141
Cork County124111414121210544746,91230
Kerry01381113141412755716,93627
Limerick City1013101315161576677,55035
Limerick County00151114151514655717,54331
Tipperary011510121314138671117,62837
Waterford City 12591216181675454,68433
Waterford County0126111315161474578,51932
Galway City012471216181595546,49524
Galway County01261114151312765823,43126
Leitrim00161214131211667123,43429
Mayo1125814161413756913,22328
Roscommon00161213151211655115,33329
Sligo1127911131413106698,51329
Cavan013914161312965576,99924
Donegal01261415141311645814,08525
Monaghan0128131212141475475,11333
                
Total113711131314127557486,29130
                
Table 5 BER Ratings by Dublin Postal District
 % of row
CountyEnergy Rating Average age
AB1B2B3C1C2C3D1D2E1E2FGTotal
Dublin 103778911121497674,84727
Dublin 215767910121297682,60332
Dublin 300256791113101012154,75153
Dublin 401479910141498886,37441
Dublin 50024681117151110974,28542
Dublin 61235667111310910185,02555
Dublin 6W012798913138910112,51248
Dublin 7 0124871214101012186,15855
Dublin 803797781012989127,70240
Dublin 910367891214101010105,47144
Dublin 10  35151512101077881,85840
Dublin 1112913121010111065656,16228
Dublin 12 1345681112111113144,65351
Dublin 1311412111211131276543,36329
Dublin 14025899101214108875,10837
Dublin 15125101215151712532110,81917
Dublin 160159101212161575434,36926
Dublin 17 2911131514151053212,38322
Dublin 18281215151299832215,67716
Dublin 20 07128791314128651,16030
Dublin 220014812141720106433,47824
Dublin 241125101414171496527,53920
                
Total02589101113138777106,29735
                
Table 6 BER Ratings by Main Space Heating Fuel
              % of row
Fuel TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Mains Gas1251114151413105443183,502
Bulk LPG136172018139632117,242
Bottled LPG013812141212154459658
Heating Oil012611151616136555193,300
Electricity11112581318131091869,648
Coal   0011413141316382,865
Smokeless Fuel   0001316181315342,332
Peat 0  011311111416431,236
Wood Pellets & Chips271524131310542122983
Wood Logs2122333713991133495
Solid Multi-Fuel 0000127131412153617,810
               
Total013711131314127657480,071
               
Table 7 BER Ratings by Main Water Heating Fuel
              % of row
Fuel TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Mains Gas1251114151413105443182,234
Bulk LPG136182018138632117,193
Bottled LPG003812141411155458691
Heating Oil012611151616136555191,846
Electricity11112581317131092073,357
Coal0001122515141417302,732
Smokeless Fuel   0011418201416262,186
Peat   0011411121416401,269
Wood Pellets & Chips271524131210542221989
Wood Logs22234359131081128450
Solid Multi-Fuel00000127131513163217,124
               
Total013711131314127657480,071
               
Table 8 Main Space Heating Fuel by County
      % of row
CountyFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
Carlow374610626,938
Dublin 01-247262110102,570
Dublin County7712101033,271
Kildare4639103117,561
Kilkenny30538828,337
Laois314871317,374
Longford262191344,257
Louth553753112,265
Meath414693113,615
Offaly95892316,157
Westmeath1653141539,117
Wexford1711411316,039
Wicklow424296113,659
Clare11621411314,852
Cork City671120208,696
Cork County4240124246,615
Kerry167188516,860
Limerick City542021407,458
Limerick County2948148117,503
Tipperary1367811117,565
Waterford City611421304,676
Waterford County275213628,483
Galway City174137226,423
Galway County767167323,363
Leitrim068141153,432
Mayo373138313,192
Roscommon37510935,332
Sligo26124858,497
Cavan86910756,931
Donegal08186513,953
Monaghan8757735,080
       
Total38401552480,071
       
Table 9 Main Space Heating Fuel by Period of Construction
      % of row
Period of ConstructionFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
1700-189929392110111,983
1900-192931391810124,750
1930-19494238910123,859
1950-1966444267137,284
1967-1977365347149,499
1978-1982335448134,148
1983-19933149117255,332
1994-19993239235159,827
2000-20043837213287,837
2005-20094828182488,795
2010-2014572712136,757
       
Total38401552480,071
       
Table 10 Main Space Heating Fuel by Type of Dwelling
      % of row
Dwelling TypeFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
Apartment43550124,049
Ground-floor apartment476431227,125
Mid-floor apartment411571132,982
Top-floor apartment423531227,825
Basement Dwelling309592 105
Maisonette53736234,573
House187045339,465
Detached house1572462122,727
Semi-detached house4741471121,644
End of terrace house582587132,844
Mid-terrace house592397166,732
       
Total38401552480,071
       
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
1700-18996953465559105148157144117107118
1900-19296350445242911191231209590100
1930-1949525844505276110120109848197
1950-19667062525556611161241128786103
1967-19776665595671661311391078483109
1978-19826463645410070137143968382110
1983-1993585856584774146150958280110
1994-19996763586759771521621018484111
2000-20047570707770911651781039591115
2005-200981717278989616819110710098110
2010-20148476727386100192215119115109139
             
All7566667056871461561049088110
             
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
1700-1899436425389489395475418414396418370406
1900-1929473434418513389465430422393431387414
1930-1949367365299435485461382401346384337368
1950-1966421348321419491300347357314348310333
1967-1977388335284398408330294297285286264289
1978-1982331297244296309308246251260249228251
1983-1993341313259308261284229233250258235242
1994-1999282289244289248265209208234262236227
2000-2004254249210248324221190193215225199207
2005-2009170189159191243162152162174170156167
2010-201420411091116132881039990918597
             
All229255200260365231236245248271261247
             
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
1700-1899102978611183112107107969987100
1900-19291129994116851131121109510390102
1930-1949858365971071109810481907990
1950-196610078699210663889072797179
1967-1977937560869976747466676370
1978-1982806853657773626362585361
1983-1993827258705765575859615458
1994-1999666655665860515154615454
2000-2004585547547248464750504348
2005-2009374034415334363940373438
2010-2014462318243018242319181721
             
All525644578051596158626059
             
        
        
Table 14 Dwellings with Multiple BER Ratings
               % of total
Earliest YearLatest YearTotal
A2A3B1B2B3C1C2C3D1D2E1E2FG
A1    0         0
A2          0   0
A3 0000         0
B1 0000000 0    1
B2  00100000  0 1
B3 00111000000  3
C1 00022100000006
C2  0013210000008
C3 000123210000011
D1  00123321000013
D20000122232100014
E1  00111122100010
E2 00011111211009
F 000111112111010
G0001121112111214
                
Total00141217161413105332100
                
Table 15 BER Ratings Weighted to National Level
              % of row
Dwelling TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Apartment126910101011128669163,087
Detached house0127101213131265611675,347
Semi-detached house01159131516138666434,142
Terraced house0126101111131297811262,267
               
Total0126101213141276691,534,842
               

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. Electricity used for cooking, refrigeration, laundry and other appliance use are 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 80,000 domestic dwellings each year. Hence there were 486,000 unique domestic BERs (one per dwelling) completed in the period 2009 to the end of September 2014. 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 2009-2014 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 September 2014; 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.

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