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E-mail: environment@cso.ie John Golden (+353) 1 4984218 Karen Keane (+353) 1 4984076
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, 13 October 2017, 11am

Domestic Building Energy Ratings

Quarter 3 2017

Table A: BER Ratings by Period of Construction
% of row
Period of constructionEnergy rating 
ABCDEF-GTotal
1700-19770418252033219,606
1978-1999053936136215,093
2000-200408592372131,092
2005-2009135501031127,285
2010-20143755610010,479
2015-2017945000013,723

94% of dwellings built during 2015-2017 were "A" rated

Figure 1: BER Ratings by Period of Construction
go to full release

Table A shows Building Energy Ratings (BER) by period of construction. Changes in the building regulations have resulted in much improved ratings in recent years: 37% of dwellings built in the period 2010-2014 received an "A" rating and this improved to 94% for dwellings built during 2015-2017. The proportion of "E" to "G" rated dwellings decreased from 53% for dwellings built before 1978 to 0% for dwellings built from 2010 onwards (see Figure 1).

The number of Building Energy Rating (BER) audits conducted on dwellings in the third quarter of 2017 was 22,738 which was 7% above the number of audits conducted during the same quarter in 2016. The cumulative total of BER audits conducted since January 2009 was 791,090 (see Table 1). This figure includes some dwellings that have had more than one BER audit hence the actual number of dwellings with BER ratings is 717,278 (see Table 2).

Detached and semi-detached houses were the most common dwelling types to be audited since 2009, each representing about 26% of the total number of audits (see Table 3). These types of houses had similar energy ratings with approximately 50% of each dwelling type receiving a rating of “C” or higher.

Dublin County had the highest combined “A” and “B” rating at 23% (see Table 4). In contrast, Offaly had the highest proportion of combined “F” and “G” rating at 20%.
Dublin 18, with an average dwelling age of 17 years, had the highest proportion of combined “A” and “B” rating at 39% (see Table 5). In contrast, Dublin 7 had the highest proportion of combined “F” and “G” rating at 27%, with an average dwelling age of 56 years.

Overall, Heating Oil and Mains Gas were the two most prevalent main space heating systems accounting for 78% of all dwellings audited (39% each), followed by Electricity at 15% (see Table 6). Of the dwellings using Mains Gas, 20% were rated “A” or “B”, compared with 9% for those using Heating Oil which was the main space heating system for 71% of detached houses.
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) (see Tables 12 and 13).

Table 14 examines dwellings that have had more than one BER audit carried out. The earliest assessment indicated that only 5% 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 3% in the latest assessment (see Table 14 and Figure 2).

 

 

EarliestLatest
A00
B101
B214
B3412
C1717
C2916
C31114
D11412
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 51% of dwellings in the actual BER data (see also Figure 3). In addition, 15% of dwellings would have received "F" or "G" ratings at the national level, whereas actual BER data indicates this figure to be 13%.

National DataBER database
A22
B111
B223
B367
C11011
C21213
C31313
D11313
D21211
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 (2009-2017) 1
number
Period200920102011201220132014201520162017Total
January4,1024,6738,5636,5266,9687,0066,5215,2535,77455,386
February6,3215,6169,0236,3078,5247,5407,6596,8636,86464,717
March8,7676,1538,9396,5128,2088,3857,2627,5357,70769,468
April8,0395,4837,7814,4418,2988,7337,5887,3937,18764,943
May7,9225,4758,8765,8758,6458,7287,7147,9548,25669,445
June8,7305,7807,4634,8637,2638,2188,0017,4457,82165,584
July8,7765,9697,2585,5357,0969,3967,6766,5587,24365,507
August7,2706,4337,5325,0456,9738,1647,6497,0297,37463,469
September7,5197,4288,8564,9738,2819,9198,3587,6718,12171,126
October6,5888,4049,5676,6908,98010,7729,2207,936 68,157
November6,97511,6179,6208,8089,60610,8998,4169,028 74,969
December6,3468,0169,4806,3676,9387,7797,3126,081 58,319
           
Total87,35581,047102,95871,94295,780105,53993,37686,74666,347791,090
1 Includes all Certificates for Dwellings
Table 2 BER Ratings by Period of Construction (2009-2017)
% of row 
Period of ConstructionEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
1700-18990012234710910143818,472
1900-19290012234710910143739,151
1930-194900134579121010132635,115
1950-1966001356811141111131754,764
1967-197700136812161711109872,104
1978-198200138131518181065348,675
1983-19930014913162018954380,068
1994-199900151015192015753186,350
2000-200400171622221594321131,092
2005-200913112124179642110127,285
2010-2014372916932110000010,479
2015-201794321000000013,723
               
Total213711131313117557717,278
– No dwelling received this BER rating for this dwelling type
Table 3 BER Ratings by Type of Dwelling (2009-2017)
% of row 
Dwelling TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Apartment14111312710101065564,353
Ground-floor apartment113810111012141076740,780
Mid-floor apartment351112121212129533349,093
Top-floor apartment1148109912149651042,145
Basement Dwelling122558881210931209
Maisonette12712131110111364487,429
House12391214141311544837,598
Detached house2127111313131165610191,315
Semi-detached house411511151515127554189,069
End of terrace house31151013131311767952,344
Mid-terrace house212813131112117668102,943
               
Total213711131313117557717,278
– No dwelling received this BER rating for this dwelling type
Table 4 BER Ratings by County (2009-2017)
% of row  
CountyEnergy Rating Average age
AB1B2B3C1C2C3D1D2E1E2FGTotal
Carlow1127121414151165579,98129
Dublin 01-24324710111113128667158,14636
Dublin County92481113121211544450,85327
Kildare61371214151411543528,50124
Kilkenny11271213131412755911,88534
Laois1128111514129666911,21629
Longford0127111212151266796,20327
Louth2239141514139544619,33832
Meath5138141614129544522,70825
Offaly1114912121111999119,72833
Westmeath012710131514116561013,47330
Wexford11251014151513855823,77228
Wicklow41271112131311756820,55132
Clare1026913151412865819,86531
Cork City11481212111212866718,91244
Cork County214111514121110544764,58232
Kerry11371113131412755823,90128
Limerick City10141114151513756711,78736
Limerick County10261114151413755721,73532
Tipperary01159121314128671124,10439
Waterford City2125111315171375467,68635
Waterford County21261113141513745711,69634
Galway City2125912161714865410,92624
Galway County11261114151311765830,56628
Leitrim00261214131210667115,49530
Mayo11258131514137561019,50031
Roscommon00151114161210756128,59231
Sligo1127912131313966912,07430
Cavan1138141612129655910,85827
Donegal11261315141311655821,58828
Monaghan1128131112141275587,05634
                
Total213711131313117557717,27832
Table 5 BER Ratings by Dublin Postal District (2009-2017)
% of row  
Dublin Postal DistrictEnergy Rating Average age
AB1B2B3C1C2C3D1D2E1E2FGTotal
Dublin 1226791011131386576,84230
Dublin 2146781012131286573,81536
Dublin 3102688911129910146,72354
Dublin 411479910141397878,54743
Dublin 5112579111614119866,58243
Dublin 62135678111310910166,99258
Dublin 6W312688912138910103,70049
Dublin 700136991213101011169,17856
Dublin 8126878912138781111,43843
Dublin 9303681010111398998,07545
Dublin 1024131513121187882,93543
Dublin 113271212111111965658,84630
Dublin 1211246891213101012127,58752
Dublin 1371411111111121166545,24529
Dublin 1443588910111397767,50637
Dublin 15824101315141411422115,99017
Dublin 166148111312141375426,87327
Dublin 17517914191413842213,82524
Dublin 18471215151299832218,07717
Dublin 2044898881313107541,81830
Dublin 22101491315181996335,44026
Dublin 2431251115151614754212,11222
                
Total324710111113128667158,14636
– No dwelling received this BER rating in this postal district
Table 6 BER Ratings by Main Space Heating Fuel (2009-2017)
% of row  
Fuel TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Mains Gas325101515141295442277,584
Bulk LPG2261721181396321110,291
Bottled LPG0138131412121254510893
Heating Oil012612151615126555275,795
Electricity51113681316119817104,420
Coal00011412151418353,535
Smokeless Fuel00001312151418364,981
Peat0001311121317421,449
Wood Pellets & Chips3611201315117532221,255
Wood Logs42232349129101032596
Solid Multi-Fuel00000127131414163327,462
               
Total213711131313127557708,261
– No dwelling received this BER rating for this main space heating fuel type
Table 7 BER Ratings by Main Water Heating Fuel (2009-2017)
             % of row 
Fuel TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Mains Gas325101516141295432275,980
Bulk LPG2261721181396321110,244
Bottled LPG003813151311126459975
Heating Oil012612151615126555273,689
Electricity51113681316118819109,946
Coal0001112513151519273,408
Smokeless Fuel0011414171619284,440
Peat0011411131317401,481
Wood Pellets & Chips3611201315117532321,255
Wood Logs32133351013991127546
Solid Multi-Fuel00000128141514172926,297
               
Total213711131313127557708,261
– No dwelling received this BER rating for this main water heating fuel type
Table 8 Main Space Heating Fuel by County (2009-2017)
% of row  
CountyFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
Carlow354610629,973
Dublin 01-247362010152,916
Dublin County7712101049,526
Kildare4738113128,391
Kilkenny295298211,838
Laois3145715111,191
Longford262191336,138
Louth553563119,115
Meath4343103122,686
Offaly105592419,623
Westmeath14541514313,431
Wexford1701511323,668
Wicklow4341105120,443
Clare13591511319,824
Cork City739162018,709
Cork County4041134264,209
Kerry1642010523,772
Limerick City5520214011,654
Limerick County2849149121,651
Tipperary13651011124,026
Waterford City621420307,670
Waterford County2354157211,639
Galway City2039336210,848
Galway County767167330,485
Leitrim066161255,493
Mayo373139319,464
Roscommon47211938,591
Sligo163219512,055
Cavan968108410,789
Donegal08196421,424
Monaghan9738737,019
       
Total39391562708,261
Table 9 Main Space Heating Fuel by Period of Construction (2009-2017)
% of row  
Period of ConstructionFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
1700-189929382210118,040
1900-192930401910138,627
1930-1949433899135,027
1950-1966464166154,614
1967-1977385047171,458
1978-1982365248148,450
1983-19933446118279,611
1994-19993338235185,795
2000-200439361942130,309
2005-200947301824123,717
2010-2014562615129,748
2015-2017587330112,865
       
Total39391562708,261
Table 10 Main Space Heating Fuel by Type of Dwelling (2009-2017)
% of row 
Dwelling TypeFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
Apartment46447124,098
Ground-floor apartment477431238,963
Mid-floor apartment401580145,229
Top-floor apartment413531240,194
Basement Dwelling28106022188
Maisonette53737227,340
House187055337,578
Detached house1571562191,166
Semi-detached house4839571188,801
End of terrace house592487152,149
Mid-terrace house6022971102,555
       
Total39391562708,261
Table 11 Average Floor Area by Period of Construction and Type of Dwelling (2009-2017)
m2
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-18996954465754105148158147116106119
1900-19296451445343911191241209790100
1930-1949516145515377110120110848298
1950-19667063545558671161251138886104
1967-197766655956108641321391088584109
1978-19826465645510067137142978482109
1983-1993585855575870147149958281108
1994-19996763586761761531611018383110
2000-20047471697768891661771039591114
2005-200981727279899517019110610198111
2010-20148478717686101195214122117110141
2015-2017808180830125188199127126120136
             
All7667667059861471561059189110
Table 12 Average Primary Energy Use by Period of Construction and Type of Dwelling (2009-2017)
kWh/m2/year
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-1899432421385487408478417409380418366401
1900-1929480429436500379449414420387417377408
1930-1949363350284423460443375401346367328364
1950-1966415333295393515326337354309339303327
1967-1977387314257359311308290299284283256287
1978-1982335286241291309304245252256248224249
1983-1993346302255299314278228233244247225239
1994-1999285278239279271258206208229250227224
2000-2004253240206240268211189193213219195205
2005-2009170188161191183164152162176172157168
2010-201420510991116132921009783878393
2015-2017103665362084585756555256
             
All222249197256327233233242238259252241
 
Table 13 Average Carbon Dioxide Emissions by Period of Construction and Type of Dwelling (2009-2017)
kgCO/m2/year
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-1899101968511087112107106921008699
1900-1929114989711283107107109939988101
1930-1949858061931001029610482857689
1950-19669974638511369859070776977
1967-1977927054787771737466666069
1978-1982816551637771616361575160
1983-1993836856676963565857585157
1994-1999676253626157515153585153
2000-2004585245525845464750484248
2005-2009363934403634363941373438
2010-2014462318233018232217181720
2015-201720131012018121211111011
            
All505542567151586055595757
 
Table 14 Dwellings with Multiple BER Ratings (2009-2017)
                 % of total
Earliest YearLatest YearTotal
A1A2A3B1B2B3C1C2C3D1D2E1E2FG
A1000
A20000
A30000000
B1000000000
B20000000000001
B300002100000004
C100023100000007
C200023210000009
C30000133210000011
D10000123321000014
D20000122232100014
E10000111122100010
E2000011111111008
F000011111111109
G0000111111111212
                 
Total000141217161412105332100
– No dwelling received this BER rating combination for the earliest and latest assessments
Table 15 BER Ratings Weighted to National Level (2009-2017)
             % of row  
Dwelling TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Apartment226911111011117559164,536
Detached house2127101213131265611675,748
Semi-detached house211510141516137666434,352
Terraced house2116101212121287810262,696
               
Total2126101213131276691,537,333

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 717,278 unique domestic BERs (one per dwelling) completed in the period 2009 to the end of September 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 B. 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 B: 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 September 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 Tables 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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