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For more information on this release:
E-mail: environment@cso.ie John Golden (+353) 1 4984218 James O'Brien (+353) 1 4984101
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, 11 January 2018, 11am

Domestic Building Energy Ratings

Quarter 4 2017

Table A: BER Ratings by Period of Construction
% of row
Period of constructionEnergy rating 
ABCDEF-GTotal
1700-19770418252033224,945
1978-1999053936136218,796
2000-200408592372133,753
2005-2009135501031129,407
2010-20143755610010,552
2015-2017954000016,868

Over 87,000 Domestic Building Energy Rating audits conducted in 2017

go to full release

There were 87,615 domestic Building Energy Rating (BER) audits conducted in 2017 which was an increase of 1% on 2016 (see Table 1). The dwellings built in 2015-2017 were considerably more energy efficient than in previous periods with 95% given an “A” rating (see Table A and Figure 1).

Over 800,000 audits have been conducted in the period 2009-2017 (see Table 1). Mid-floor apartments are the most energy efficient with 31% of these awarded an "A" or "B" rating. In contrast only 6% of Basement dwellings received an "A or "B" rating (see Table 3).

Dublin County had the highest combined “A” and “B” rating, at 24% (see Table 4). Offaly, Limerick City and Roscommon had the lowest proportion of combined “A” and “B” rating at 7%.

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). The highest proportion of combined “F” and “G” rating was 27% for Dublin 7.

Heating Oil (39%) and Mains Gas (39%) were the main heating fuels used (see Table 9). Electricity was next at 15%, Solid Fuel at 5% and Liquid Petroleum Gas (LPG) at 2%. 21% of dwellings using Mains Gas as their main heating system had an "A" or "B" rating (see Table 6).

Domestic Building Energy Ratings Released December 2017 Figure 2 (XLS 36KB)
EarliestLatest
A00
B101
B214
B3412
C1717
C2916
C31213
D11412
D2149
E1105
E283
F93
G122
Domestic Building Energy Ratings Released December 2017 Figure 3 (XLS 36KB)
National DataBER database
A23
B111
B223
B367
C11011
C21213
C31313
D11313
D21211
E177
E265
F65
G97
Table 1 Domestic Building Energy Ratings Certificates (2009-2017) 1
number
Period200920102011201220132014201520162017Total
January4,1024,6738,5656,5266,9687,0066,5215,2545,68355,298
February6,3215,6219,0246,3098,5247,5417,6606,8636,80764,670
March8,7686,1538,9406,5138,2088,3857,2627,5367,62469,389
April8,0395,4797,7794,4418,2998,7337,5887,3937,13364,884
May7,9235,4768,8785,8758,6458,7287,7157,9548,17469,368
June8,7305,7807,4634,8627,2638,2188,0017,4457,68765,449
July8,7765,9687,2585,5357,0969,3967,6746,5587,12565,386
August7,2716,4337,5325,0456,9728,1647,6497,0297,24963,344
September7,5207,4288,8544,9738,2829,9198,3587,6747,97070,978
October6,5888,4059,5676,6908,98010,7729,2217,9358,06876,226
November6,97311,6159,6198,8079,60510,8998,4159,0248,40483,361
December6,3448,0169,4796,3666,9387,7787,3126,0815,69164,005
           
Total87,35581,047102,95871,94295,780105,53993,37686,74687,615812,358
1 Includes all Certificates for Dwellings
Table 2 BER Ratings by Period of Construction (2009-2017)
% of row 
Period of ConstructionEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
1700-18990012234710910143818,918
1900-19290012234710910143740,217
1930-194900134579121010132635,900
1950-1966001356811141111131756,136
1967-19770013691216171199873,774
1978-198200138131518181065349,487
1983-19930014913162018854381,541
1994-199900151015192014743187,768
2000-200400171622211594321133,753
2005-200913112124179642110129,407
2010-20143729161042110000010,552
2015-201795310000000-0-16,868
               
Total313711131313117557734,321
– 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
Apartment14111312710101065564,337
Ground-floor apartment213810111012141076741,604
Mid-floor apartment351112121212128433350,172
Top-floor apartment1148109912149651043,048
Basement Dwelling1-22558871210931210
Maisonette12712131110101264487,603
House12391214141311544837,408
Detached house2127111313131165510196,134
Semi-detached house411511151515126554194,149
End of terrace house41151013131311767953,907
Mid-terrace house312813131112117668105,749
               
Total313711131313117557734,321
– 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
Carlow11271214141511655710,15529
Dublin 01-24424710111113128667162,71836
Dublin County92481113121210544452,26427
Kildare61371214151411543529,37824
Kilkenny11271213131412755812,09334
Laois1128111514129666911,39429
Longford0227111212151165796,32627
Louth3239151513129544619,81532
Meath6138141614129544523,40024
Offaly1114913121111989119,97634
Westmeath012710131514116561013,73630
Wexford11251014151512755824,31128
Wicklow41271112121311756820,96232
Clare1126913151412765820,11732
Cork City11481212111212866719,54744
Cork County214111514121110544765,98532
Kerry11371113131412755824,33128
Limerick City11141215151513755712,10436
Limerick County10261114151413655721,96532
Tipperary01159121314128671124,68439
Waterford City2125111315161375457,88235
Waterford County21261213141513645711,89834
Galway City2125913161714865411,23124
Galway County11271114151311755831,00728
Leitrim00261214131210667115,60931
Mayo11258131514137561019,86631
Roscommon00151115161210756128,86631
Sligo11271012131313866912,22930
Cavan1138141612129655911,10127
Donegal11261315141311655822,14028
Monaghan2238121112141275587,23134
                
Total313711131313117557734,32132
Table 5 BER Ratings by Dublin Postal District (2009-2017)
% of row  
Dublin Postal DistrictEnergy Rating Average age
AB1B2B3C1C2C3D1D2E1E2FGTotal
Dublin 1226791011131386586,94430
Dublin 2346681012131286573,94935
Dublin 32026889111210910136,84655
Dublin 411479910141397878,69543
Dublin 5212579111614109866,79343
Dublin 63134678111310910167,15658
Dublin 6W312688912138910103,81149
Dublin 710136991213101011169,43956
Dublin 8126878912138781111,66744
Dublin 9303781010111398998,26045
Dublin 101.24131513121187873,05143
Dublin 1142712121111111065649,14330
Dublin 1211246891213101012117,91453
Dublin 13101411101111121165435,55528
Dublin 1443588910121397767,68337
Dublin 15924101315141410422116,51517
Dublin 166148111312141375427,08327
Dublin 17516914191413842213,88424
Dublin 18571215151299732218,25417
Dublin 2054798881313106541,88130
Dublin 22101491315181895335,64227
Dublin 2441251115141513754112,55322
                
Total424710111113128667162,71836
– 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 Gas425101515141295442285,049
Bulk LPG2261721181396321110,489
Bottled LPG0138131412121254510904
Heating Oil012612151615126555281,009
Electricity61113681316118817107,790
Coal--00011412151418353,510
Smokeless Fuel-0-0001413151418375,145
Peat-0--001311131317421,458
Wood Pellets & Chips3611201315117532221,268
Wood Logs42232349139101131597
Solid Multi-Fuel00000127131414163427,820
               
Total313711131313117557725,039
– 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 Gas425101515141295432283,394
Bulk LPG2261721181396321110,436
Bottled LPG013814151311126459987
Heating Oil012612151615126555278,855
Electricity61113681316118819113,470
Coal0001112513151519273,385
Smokeless Fuel---0011414161519294,582
Peat---0011411131317391,487
Wood Pellets & Chips3611201315117532321,266
Wood Logs32133351013991127548
Solid Multi-Fuel00000127141515172926,629
               
Total313711131313117557725,039
– 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
Carlow3646116210,147
Dublin 01-247362010157,293
Dublin County7612111050,840
Kildare4837113129,267
Kilkenny305198212,043
Laois3145715111,369
Longford262191336,261
Louth553563119,588
Meath4343103123,378
Offaly1055102419,865
Westmeath14541513313,682
Wexford1701511324,207
Wicklow4340105120,854
Clare12591511320,076
Cork City739162019,407
Cork County4041134265,611
Kerry1642010524,201
Limerick City5520214011,971
Limerick County2848148121,895
Tipperary14651011124,606
Waterford City621420307,866
Waterford County2254167211,841
Galway City2039335211,149
Galway County767167330,924
Leitrim066161265,607
Mayo373139319,829
Roscommon471111038,865
Sligo163219512,210
Cavan968108511,021
Donegal08096421,972
Monaghan9739737,194
       
Total39391552725,039
Table 9 Main Space Heating Fuel by Period of Construction (2009-2017)
% of row  
Period of ConstructionFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
1700-189929382210118,474
1900-192930391910139,673
1930-1949433899135,812
1950-1966464066155,982
1967-1977385047173,171
1978-1982365248149,259
1983-19933446117281,072
1994-19993338235187,221
2000-200439361942132,956
2005-200946301824125,769
2010-2014562615129,821
2015-2017586340115,829
       
Total39391552725,039
Table 10 Main Space Heating Fuel by Type of Dwelling (2009-2017)
% of row 
Dwelling TypeFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
Apartment46447124,084
Ground-floor apartment477431239,734
Mid-floor apartment401580146,161
Top-floor apartment413531241,033
Basement Dwelling27106022188
Maisonette53736227,503
House187055337,388
Detached house1571662195,982
Semi-detached house4839571193,871
End of terrace house602487153,716
Mid-terrace house6122971105,379
       
Total39391552725,039
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
1700-18996854465654105148158147115105119
1900-19296451445343891191241209890100
1930-1949516245515377110120110848298
1950-19667063545658671161251138886104
1967-197767655956101641321391088584109
1978-19826466635510067137142978482109
1983-1993585955575471147149958280108
1994-19996763586761761531611018383110
2000-20047471697768891661771039591114
2005-200981727279929517019110610198111
2010-20148478717686101195213122117109141
2015-2017808280830126188198126124119134
             
All7667667059861481561059289110
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
1700-1899434418384486408477417408379417366400
1900-1929480430435499381448414420385416376407
1930-1949363349284422460446375401345366327363
1950-1966415332292391515314336354308338302326
1967-1977385312256359319307290299284282255287
1978-1982335285241291309304245252255247223249
1983-1993346301254298315278228233244246224239
1994-1999284277238278268256206208228249226223
2000-2004253239206239268210189193213218194205
2005-2009170188161191179164152162175171157168
2010-201420511091116132921009783888493
2015-2017103645260076585756555256
             
All222248196255325232233242236257250240
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
1700-1899102958411087112107105921008699
1900-1929114989611283106107109939988101
1930-1949858061931001039610481857688
1950-19669974628511367858970766877
1967-1977927054787770737466665969
1978-1982816451637771616361575160
1983-1993836856677063565857575157
1994-1999666253626157505153575152
2000-2004585245525845464750484248
2005-2009363934403534363941373438
2010-2014462318233018232217181720
2015-201720121011016121211111011
             
All505442557051586055595757
Table 14 Dwellings with Multiple BER Ratings (2009-2017)
                 % of total
Earliest YearLatest YearTotal
A1A2A3B1B2B3C1C2C3D1D2E1E2FG
A1000
A20000
A30000000
B10000000000
B20000000000001
B3000012100000004
C1000023100000007
C200023210000009
C30000133210000012
D10000123321000014
D20000122232100014
E10000111122100010
E2000011111111008
F000011111111109
G0000111111111212
Total00014121716131295332100
– 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
Apartment226911111011117559164,586
Detached house2127101213131265611675,724
Semi-detached house211510141516137665434,334
Terraced house2116101212121287810262,749
               
Total2126101213131276691,537,392
               

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 734,321 unique domestic BERs (one per dwelling) completed in the period 2009 to the end of December 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 December 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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