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For more information on this release:
E-mail: environment@cso.ie John Golden (+353) 1 4984218 Anne-Marie Griffin (+353) 1 4984216
For general information on CSO statistics:
information@cso.ie (+353) 21 453 5000 Visit StatCentral.ie, the portal to Ireland's official statistics On-line ISSN 2009-7441
CSO statistical release, 21 April 2017, 11am

Domestic Building Energy Ratings

Quarter 1 2017

% of row
Dwelling TypeEnergy Rating Total
A-BCDEF-G
Apartment29292011114,391
Ground-floor apartment123126181338,693
Mid-floor apartment3036218646,881
Top-floor apartment142727161640,055
Basement Dwelling517172239198
Maisonette21332410126,999
House15412491237,900
Detached house1237251115179,948
Semi-detached house1041271210178,343
End of terrace house103624141649,012
Mid-terrace house133723131497,124

30% of Mid-floor apartments are "A" or "B" rated

Figure 1 BER Ratings by Type of Dwelling
go to full release

A total of 20,604 Building Energy Rating (BER) audits were conducted on dwellings in the first quarter of 2017, bringing the cumulative total of BER audits conducted since January 2009 to 745,347 (see Table 1). The number of BER audits carried out in 2017 represents an increase of 4.9% compared with the same period in 2016. 

Detached houses and semi-detached houses were the most common dwelling types to be audited since 2009, each representing 26% of the total number of audits. They also had similar energy ratings with approximately 50% of each dwelling type receiving a rating of “C” or higher. Mid-Floor apartments had the highest percentage of "A" and "B" ratings at 30% (see Figure 1). 

Dublin County had the highest combined “A” and “B” rating at 21%. In contrast, Limerick City at 6% had the lowest proportion of combined “A” and “B” rating (see Table 4).

Dublin 18, with an average dwelling age of 17 years, had the highest proportion of combined “A” and “B” rating at 38%. In contrast, Dublin 7 had the highest proportion of combined “F” and “G” rating at 27%, with an average dwelling age of 56 years (see Table 5). Dwellings with a BER rating in Dublin 10 had an average age of 42 years, and was the only Dublin postal district or county with no "A" or "B1" rated dwellings. 

Overall, Heating Oil and Mains Gas were the two most prevalent main space heating systems accounting for 78% of all dwellings (39% each), followed by Electricity (15%). Of the dwellings using Mains Gas, 20% were rated “A” or “B”, compared with 9% for those using Heating Oil (see Table 6). Of the dwellings built between 2010 and 2017, the majority used Mains Gas (58%), followed by Electricity (23%) and Heating Oil (17%) (see Table 9).

Electricity and mains gas were used in most apartments that were audited (see Table 10). In contrast, 71% of detached houses used Heating Oil.

Detached houses at 156 square metres had the highest average floor area (see Table 11). Dwellings constructed in the period 1900-1929 had the highest average primary energy use (408 kWh/m2/year), as well as, average carbon dioxide emissions (101 kgCO2/m2/year).  

Table 14 examines dwellings that have had more than one BER audit carried out. The earliest assessment indicated that only 6% of dwellings received either an “A” or “B” rating compared with 17% in the most recent assessment. In addition, 21% of dwellings were originally rated “F” or "G" compared with only 5% in the latest assessment (see Table 14 and Figure 2).

EarliestLatest
A00
B101
B214
B3412
C1717
C2916
C31114
D11312
D21410
E1105
E283
F93
G122
ABCDEFG
01 Mains Gas2174422942
02 Heating Oil0943281155
03 Electricity33163121818
04 Solid Fuel02419271633
05 LPG1245116522
National11137251257

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 46% of dwellings would have received a rating of “C” or higher compared with 50% of dwellings in the actual BER data (see also Figure 3).

National DataBER database
A12
B111
B223
B367
C11011
C21213
C31313
D11313
D21212
E177
E265
F65
G97
ABCDEFG
Carlow11040261157
Cavan01143211158
Clare0838271458
Cork City11336241358
Cork County1164121948
Donegal0943241158
Dublin 01-2421232261577
Dublin County51437251144
Galway City0635321565
Galway County1940251258
Kerry11137261358
Kildare41141261045
Kilkenny11038261159
Laois01239221269
Leitrim08382312711
Limerick City0540301267
Limerick County1840281257
Longford0935261379
Louth1144323946
Mayo17372712610
Meath2124522945
Monaghan11136271258
Offaly06332218911
Roscommon07412212612
Sligo1934261569
Tipperary06352714711
Waterford City1838311246
Waterford County1939291156
Westmeath010372512610
Wexford1738281358
Wicklow31036241368
National11137251257
Table 1 Domestic Building Energy Ratings Certificates 1
number
Period200920102011201220132014201520162017Total
January4,1014,6728,5636,5246,9687,0056,5205,2525,85855,463
February6,3215,6159,0236,3068,5247,5407,6576,8626,95664,804
March8,7666,1528,9396,5098,2088,3857,2617,5347,79069,544
April8,0355,4857,7814,4398,2988,7327,5877,393 57,750
May7,9265,4748,8755,8738,6458,7287,7147,954 61,189
June8,7285,7397,4634,8647,2638,2208,0017,446 57,724
July8,7785,9697,2585,5357,0969,3977,6766,558 58,267
August7,2686,4587,5315,0466,9738,1647,6497,028 56,117
September7,5207,4278,8574,9758,2819,9198,3587,667 63,004
October6,5898,4229,5676,6918,98010,7719,2227,938 68,180
November6,97611,6179,6218,8139,60610,8988,4199,033 74,983
December6,3478,0179,4806,3676,9387,7807,3126,081 58,322
           
Total87,35581,047102,95871,94295,780105,53993,37686,74620,604745,347
1 Includes all Certificates for Dwellings  
Table 2 BER Ratings by Period of Construction
             % of row 
Period of ConstructionEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
1700-18990012234710910143817,535
1900-19290012234710910143736,637
1930-194900134579121010132633,092
1950-1966001356811141111131751,684
1967-19770013691216171199868,661
1978-198200138131518181065346,803
1983-19930014913162018954376,569
1994-199900151015192015753182,730
2000-200400171522221594321124,731
2005-200913112123179642110121,610
2010-2017641710521100000019,492
               
Total213711131313127557679,544
Table 3 BER Ratings by Type of Dwelling
% of row 
Dwelling TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Apartment14111312710101065564,391
Ground-floor apartment113810101012141086738,693
Mid-floor apartment251112121212129533346,881
Top-floor apartment1148109912159651040,055
Basement Dwelling23548991310930198
Maisonette12711131110111364486,999
House12391214141311544837,900
Detached house2127111313131165610179,948
Semi-detached house311511151615127555178,343
End of terrace house31151013131311767949,012
Mid-terrace house21281313111211766897,124
               
Total213711131313127557679,544
– No data
Table 4 BER Ratings by County
% of row  
CountyEnergy Rating Average age
AB1B2B3C1C2C3D1D2E1E2FGTotal
Carlow1127121414151165579,53129
Dublin 01-24224710111113128667149,74036
Dublin County72481113131311644447,87427
Kildare51371214151411644526,71724
Kilkenny11271213131412755911,39734
Laois1128111514129666910,81229
Longford0127111212151176795,88626
Louth1239141514139544618,28232
Meath4138141615139544521,17325
Offaly1114912121111999119,29133
Westmeath013710121514116561012,88930
Wexford1125914151513855822,57728
Wicklow31271113131311756819,45232
Clare1016913151513865819,06531
Cork City12481212121212866716,67044
Cork County224111514121110544761,72732
Kerry11371113131412755822,72428
Limerick City10141113151614756711,06936
Limerick County10261114151413755721,06531
Tipperary01159121314138671123,14939
Waterford City1125111315171475467,23635
Waterford County11261113141513745711,20334
Galway City112581216171486659,80824
Galway County11261114151311765829,50027
Leitrim00261214131211667115,21430
Mayo11258131514137561018,47631
Roscommon00151114151210756128,00631
Sligo1127912131313966911,54330
Cavan1138141613129655810,34526
Donegal11261315141311655820,36328
Monaghan1128131112141375586,75834
                
Total213711131313127557679,54431
Table 5 BER Ratings by Dublin Postal District
% of row  
CountyEnergy Rating Average age
AB1B2B3C1C2C3D1D2E1E2FGTotal
Dublin 1226791011131396586,63730
Dublin 2147781012131296573,66636
Dublin 3102688911129911146,45954
Dublin 411479910131497888,20243
Dublin 5112579111614109866,17342
Dublin 62134678111310910176,68157
Dublin 6W212688913138910103,48449
Dublin 700136991213101011178,79056
Dublin 8036878912138781110,87643
Dublin 9303681010111398997,73745
Dublin 1025131613121176772,76742
Dublin 1122712121112111065558,28630
Dublin 1201246891213101012126,98352
Dublin 1351512111211121176544,87529
Dublin 1433688910121397767,12537
Dublin 15725101315141511422115,11517
Dublin 164148111412151375426,48027
Dublin 17417914191413842213,71624
Dublin 18471215161299832217,62417
Dublin 20148108881413107541,67131
Dublin 221013913141819106335,10226
Dublin 2421251215151614854211,29122
                
Total224710111113128667149,74036
– No data
Table 6 BER Ratings by Main Space Heating Fuel
             % of row 
Fuel TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Mains Gas325101516141295442261,625
Bulk LPG126172118139632119,848
Bottled LPG0138131412111354510861
Heating Oil012612151615126555262,716
Electricity4111368131712981797,963
Coal00011413151418343,566
Smokeless Fuel00001312151418354,654
Peat0001311131317421,441
Wood Pellets & Chips3612201315117532221,217
Wood Logs3223234813991132583
Solid Multi-Fuel00000127141414163326,580
               
Total213711131313127557671,054
– No data
Table 7 BER Ratings by Main Water Heating Fuel
             % of row 
Fuel TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Mains Gas325111516141295432260,092
Bulk LPG226172118139632119,801
Bottled LPG003814151410135459933
Heating Oil012612151615126555260,714
Electricity41113581316129819103,162
Coal0001112514161519273,438
Smokeless Fuel0011414171620284,171
Peat0011411131317401,472
Wood Pellets & Chips3612201314116532321,217
Wood Logs32143351013991128535
Solid Multi-Fuel00000128141514162925,519
               
Total213711131313127557671,054
– No data
Table 8 Main Space Heating Fuel by County
     % of row 
CountyFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
Carlow364710629,524
Dublin 01-247362010144,729
Dublin County7712101046,745
Kildare4738113126,610
Kilkenny295298211,350
Laois3145716110,787
Longford262191435,823
Louth563553118,065
Meath424493121,163
Offaly105592519,186
Westmeath14541514312,848
Wexford1701512322,474
Wicklow4341105119,353
Clare12591511319,025
Cork City729172016,491
Cork County4041134261,359
Kerry1651910522,612
Limerick City5520214010,936
Limerick County2849149120,984
Tipperary1365911123,072
Waterford City621420307,220
Waterford County2353157211,147
Galway City164134629,733
Galway County767167329,421
Leitrim066161265,212
Mayo372139318,441
Roscommon37311948,005
Sligo163219511,525
Cavan968108510,276
Donegal08096420,217
Monaghan8748736,721
       
Total39391562671,054
Table 9 Main Space Heating Fuel by Period of Construction
     % of row 
Period of ConstructionFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
1700-189929382210117,112
1900-192930391910136,139
1930-19494239910133,005
1950-1966464167151,539
1967-1977385147168,030
1978-1982365248146,602
1983-19933446118276,115
1994-19993338226182,210
2000-200439361942123,952
2005-200947301824118,116
2010-20175817231218,234
       
Total39391562671,054
Table 10 Main Space Heating Fuel by Type of Dwelling
     % of row 
Dwelling TypeFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
Apartment46447124,136
Ground-floor apartment477431236,969
Mid-floor apartment401580143,282
Top-floor apartment423531238,204
Basement Dwelling26106121180
Maisonette52737226,912
House187055337,880
Detached house1571562179,809
Semi-detached house4739581178,089
End of terrace house592587148,836
Mid-terrace house602297196,757
       
Total39391562671,054
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
1700-18996954465654106148158145115105118
1900-19296450445343891191241209790100
1930-1949516045515377110120110848298
1950-19667063545658651161251138886104
1967-197766655956108641321391088584109
1978-19826464635410066137142968482109
1983-1993585855575870146149958281108
1994-19996763586761761531611008383110
2000-20047471697768891661771039591114
2005-200981727278949517019110610098111
2010-20178179747986107194209126124116140
             
All7667667059861471561059188110
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
1700-1899432423387490399481417410385417365402
1900-1929480430440505378450414419388419378408
1930-1949363354284424460445377400346370329364
1950-1966415334297396515320338354309340304328
1967-1977387316257360311308291299284283257287
1978-1982335288243294309304245252257247224250
1983-1993345303256300314282228233246249225240
1994-1999282280240281271260207209231251228225
2000-2004253242207242272213189193214220196206
2005-2009170189162192189164152162176172157168
2010-201712397779613293998166686776
             
All222251199258328234233243240261253243
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
1700-1899101968511185113107106931008699
1900-19291149898114831071071099410088101
1930-1949858161931001029610382867689
1950-19669974638611368859071776978
1967-1977927154787771737466666069
1978-1982816552647771616361575261
1983-1993836957686964575858585258
1994-1999666354636158515153585253
2000-2004585345536046464750494348
2005-2009364034403734363941383438
2010-2017252015193019231814141316
             
All505543567151586056605858
Table 14 Dwellings with Multiple BER Ratings
                 % of total 
Earliest YearLatest YearTotal
A2A3B1B2B3C1C2C3D1D2E1E2FG
A100
A20000
A30000000
B1000000000
B20000000000001
B30002100000004
C100023100000007
C200023210000009
C3000133210000011
D10000123321000013
D20000122232100014
E10000111122100010
E2000011111111008
F000011111111109
G0000111111111212
                
Total00141217161412105332100
– No data
Table 15 BER Ratings Weighted to National Level
             % of row 
Dwelling TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Apartment226911111011117559164,411
Detached house1127101213131265611675,680
Semi-detached house211510141516137666434,337
Terraced house1116101212131287810262,621
               
Total1126101213131276691,537,049

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/year). 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 mainly arising from some dwellings having another BER audit undertaken.

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  

There were 679,544 unique domestic BERs (one per dwelling) completed in the period 2009 to the end of March 2017. This compares with around 1.66 million occupied 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 of non vacant households using the 2011 Census of Population. The weights were calculated by dividing the number of non-vacant 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 2009-2017 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 (four 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 mid-2015 the Census and BER files were allocated Eircodes. This makes it possible to match both files at household level as postcodes are 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 publishes a quarterly release analysing this 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. Some audit reports did not specify the type of house or apartment. 

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 2-13 only include the latest BER published for each dwelling from January 2009 to March 2017; 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 and 8. 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 average floor area, average primary energy use, and average carbon dioxide emissions 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 Total row profile in Table 2. See the entry under National representativeness for more details.

 

 

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