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For more information on this release:
E-mail: environment@cso.ie Dympna Corry (+353) 1 4984207 Berna Lawlor (+353) 1 4984210
For general information on CSO statistics:
information@cso.ie (+353) 21 453 5000 On-line ISSN 2009-7441
CSO statistical release, , 11am

Domestic Building Energy Ratings

Quarter 1 2019

Table A: BER Ratings by Period of Construction
% of row
Period of constructionEnergy rating 
ABCDEF-GTotal
1700-19770418252066249,341
1978-1999054036136236,740
2000-200409602262148,493
2005-2009135511031140,356
2010-20143655710010,839
2015-2019973000032,147

42% of Dwellings in Dublin 18 rated "A" or "B"

Figure 1: BER Ratings by Period of Construction
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Dublin 18, with an average dwelling age of 17 years, had the highest proportion of combined “A” and “B” rating at 42% (see Table 5). The average age of dwellings in Dublin 15 that have had a BER audit done was also 17 years, but the combined "A" and "B" rating was much lower at 29% than in Dublin 18. The highest proportion of combined “F” and “G” rating was 27% for Dublin 7. Roscommon had the lowest proportion of combined “A” and “B” rating at 7% (see Table 4).

Dwellings built in 2015-2019 were considerably more energy efficient than in earlier periods with 97% given an “A” rating compared with 36% in 2010-2014 and 1% in 2005-2009 (see Table A and Figure 1).

There was an increase of 10.6% in the number of dwellings receiving a BER audit in the first quarter of 2019 compared with the first quarter of 2018 (see Table 1).

Mains gas was the main space heating fuel used in 56% of the 29,967 dwellings completed during 2015-2019 and with a Building Energy Rating (BER) audit. This was a substantial increase from 2000-2004 when 40% of dwellings with a BER audit used mains gas. There were contrasting trends for heating oil and electricity with 36% of 2000-2004 built dwellings using heating oil compared with 5% for dwellings built in 2015-2019. In contrast usage of electricity increased from 19% in 2000-2004 to 38% in 2015-2019 (see Table 9).

The average floor area of all dwellings with a BER audit was 111 square metres (see Table 11). This average size varied from 156 square metres for detached houses to 58 square metres for basement dwellings.

Table 14 examines dwellings that have had more than one BER audit carried out. In their earliest assessment only 5% of dwellings received either an “A” or “B” rating compared with 19% in their most recent assessment. In contrast, 21% of dwellings were rated “F” or "G" in their first BER assessment compared with only 5% in their latest BER assessment (see Table 14 and Figure 2).

EarliestLatest
A01
B101
B214
B3413
C1718
C21016
C31213
D11412
D2139
E195
E283
F93
G122
Earliest BER ratingsLatest BER ratings
A00
B101
B214
B3412
C1717
C2916
C31213
D11412
D2149
E1105
E283
F93
G122

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 6% of dwellings in Ireland would have received a rating of “F” compared with 5% of dwellings that have had a BER assessment (see also Figure 3). Similarly, 9% of dwellings would have received a rating of "G" compared with 7% of dwellings in the actual BER data. In contrast, 3% of dwellings would have received an "A" rating at the national level, whereas 4% of dwellings that have had a BER assessment were given an "A" rating. 

National DataBER Database
A34
B111
B223
B367
C11011
C21213
C31313
D11313
D21211
E176
E265
F65
G97
National DataBER database
A23
B111
B223
B367
C11011
C21213
C31313
D11313
D21211
E177
E265
F65
G97

1Dwellings with BERs have been weighted using Census of Population 2011 data to estimate a BER profile for All Dwellings at National level (see Background Notes). 

Table 1 Domestic Building Energy Ratings Certificates (2009-2019) 1
number
Period20092010201120122013201420152016201720182019Total
January4,1024,6768,5676,5296,9697,0066,5235,2575,6855,1685,67866,160
February6,3225,6249,0276,3108,5277,5417,6606,8656,8116,4927,08378,262
March8,7696,1588,9456,5148,2098,3857,2637,5397,6276,5157,34283,266
April8,0435,4837,7774,4428,2998,7347,5907,3937,1367,053 71,950
May7,9255,4778,8785,8748,6458,7287,7167,9548,1798,391 77,767
June8,7335,7787,4654,8627,2628,2188,0017,4467,6887,590 73,043
July8,7745,9647,2575,5357,0989,3967,6756,5607,1227,511 72,892
August7,2696,4317,5325,0456,9748,1667,6487,0277,2517,156 70,499
September7,5207,4298,8534,9738,2809,9208,3577,6727,9717,229 78,204
October6,5928,4039,5666,6928,97910,7719,2207,9328,0658,317 84,537
November6,96711,6119,6178,8039,60110,8968,4129,0228,3978,274 91,600
December6,3398,0139,4746,3636,9377,7787,3116,0795,6835,743 69,720
             
Total87,35581,047102,95871,94295,780105,53993,37686,74687,61585,43920,103917,900
1 Includes all Certificates for Dwellings
Table 2 BER Ratings by Period of Construction (2009-2019)
% of row 
Period of ConstructionEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
1700-18990012234710910143821,156
1900-19290012234710910143745,535
1930-194900134579121010132539,858
1950-1966001356811141111131762,242
1967-19770013691115171199880,550
1978-198200148131518181064353,049
1983-19930014913161918854388,235
1994-199900151015192014643195,456
2000-200400181722211484221148,493
2005-200913102124189642110140,356
2010-20143629171042111000010,839
2015-2019972100000000032,147
               
Total413711131313116557817,916
– No dwelling received this BER rating for this period of construction
Table 3 BER Ratings by Type of Dwelling (2009-2019)
% of row 
Dwelling TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Apartment14111312710101065564,248
Ground-floor apartment31371011111213976745,675
Mid-floor apartment551012121211118433354,726
Top-floor apartment2148109912148651047,066
Basement Dwelling1225568711101032241
Maisonette22712131110101253478,605
House12491214141311544836,595
Detached house3127111313131165510221,594
Semi-detached house611511151514116554219,932
End of terrace house71151013121211767861,010
Mid-terrace house412813131111107667118,224
               
Total413711131313116557817,916
– No dwelling received this BER rating for this dwelling type
Table 4 BER Ratings by County (2009-2019)
% of row  
CountyEnergy Rating Average age
AB1B2B3C1C2C3D1D2E1E2FGTotal
Carlow31261214141411655711,10729
Dublin 01-24624710111112127666182,66836
Dublin County132481113121210544460,01627
Kildare101271214141310543433,86023
Kilkenny21271213131312655813,16735
Laois1139111514129666912,55529
Longford1227121212151165796,93029
Louth5239161512119534622,90231
Meath11138151613118433528,75123
Offaly11249131211118881110,91134
Westmeath11271013151411656915,09731
Wexford31251014151512755826,86829
Wicklow71271112121211755823,25932
Clare1126913151412765821,62232
Cork City21481212111211866722,00945
Cork County41411151412109544771,92232
Kerry21371112131412755826,75029
Limerick City21251214151413755713,59736
Limerick County21261114151413655723,23832
Tipperary112510121313128671127,19439
Waterford City3126121314161364468,93436
Waterford County41261213131412645712,84235
Galway City31251013161713755412,43324
Galway County21271114141311755833,22528
Leitrim00261214131110667126,21932
Mayo21259131514126561021,87932
Roscommon10151115151210756129,84632
Sligo21271012121313866913,17931
Cavan1139141612129655912,23028
Donegal11261315141311655824,87729
Monaghan2238121112141275587,82935
                
Total413711131313116557817,91632
Table 5 BER Ratings by Dublin Postal District (2009-2019)
% of row  
Dublin Postal DistrictEnergy Rating Average age
AB1B2B3C1C2C3D1D2E1E2FGTotal
Dublin 1226791011131386587,37331
Dublin 2836681011131176564,43934
Dublin 3202688911129910137,54856
Dublin 4214791010131397779,52444
Dublin 53125810111513108867,77343
Dublin 641346781113989167,92358
Dublin 6W512688101213989104,29250
Dublin 71013699121399111610,47457
Dublin 81258891012138781112,65445
Dublin 950368109111398889,46046
Dublin 102025131512121177773,47045
Dublin 1152712121111119655410,23930
Dublin 12212468101213101011118,98553
Dublin 13151410101110111065436,45327
Dublin 1473588910111287668,66537
Dublin 15132410141513139422119,02617
Dublin 168148111312141264427,96728
Dublin 17516915191413842214,09725
Dublin 18971115151298732219,38817
Dublin 208379888121396542,11931
Dublin 222014101415181785326,48827
Dublin 2481251114141512754214,31122
                
Total624710111112127666182,66836
Table 6 BER Ratings by Main Space Heating Fuel (2009-2019)
% of row  
Fuel TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Mains Gas624101515131295332321,691
Bulk LPG2261721181396221111,599
Bottled LPG113914151212125559971
Heating Oil112712151615126555307,064
Electricity111123681315108716123,635
Coal00011411141419353,388
Smokeless Fuel00001412151417385,706
Peat0012310131217421,475
Wood Pellets & Chips2610191315117532321,369
Wood Logs42222349139101030604
Solid Multi-Fuel00000127131414163529,565
               
Total413711131313116557807,067
– No dwelling received this BER rating for this main space heating fuel type
Table 7 BER Ratings by Main Water Heating Fuel (2009-2019)
             % of row 
Fuel TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Mains Gas624111515131295332319,930
Bulk LPG2261721181396221111,549
Bottled LPG0039141512101264581,071
Heating Oil112712151615126555304,622
Electricity101123681215108718130,008
Coal0001112513151619273,278
Smokeless Fuel0011414161519295,061
Peat0012411131217391,500
Wood Pellets & Chips3611201315117632321,358
Wood Logs322333511131091126558
Solid Multi-Fuel00000127141414173028,132
               
Total413711131313116557807,067
– No dwelling received this BER rating for this main water heating fuel type
Table 8 Main Space Heating Fuel by County (2009-2019)
% of row    
CountyFuel Type 
Mains GasHeating OilElectricitySolid FuelLPGTotal
Carlow3546126211,099
Dublin 01-247362010176,520
Dublin County7612111058,005
Kildare4836123133,736
Kilkenny2951108213,110
Laois3245814112,528
Longford262201346,865
Louth573472122,630
Meath4739103128,728
Offaly11551023110,791
Westmeath14541613315,042
Wexford1701511326,759
Wicklow4339125123,143
Clare13581611321,578
Cork City729162021,862
Cork County3941144271,549
Kerry1642010526,590
Limerick City5619204013,464
Limerick County2849148123,167
Tipperary14641011127,110
Waterford City621421308,911
Waterford County2153176212,784
Galway City2040325212,331
Galway County767177333,126
Leitrim166161166,216
Mayo372148321,831
Roscommon471121039,845
Sligo163219513,157
Cavan968118512,148
Donegal08196424,647
Monaghan9739737,795
 
Total40381552807,067
Table 9 Main Space Heating Fuel by Period of Construction (2009-2019)
% of row  
Period of ConstructionFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
1700-18992938229120,677
1900-192930392010144,901
1930-1949433899139,754
1950-1966474076162,050
1967-1977395056179,920
1978-1982365248152,809
1983-19933446117287,755
1994-19993338235194,866
2000-200440361942147,659
2005-200946301824136,607
2010-20145526151210,102
2015-2019565380129,967
       
Total40381552807,067
Table 10 Main Space Heating Fuel by Type of Dwelling (2009-2019)
% of row 
Dwelling TypeFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
Apartment46447123,996
Ground-floor apartment477431243,497
Mid-floor apartment401580149,885
Top-floor apartment413541244,768
Basement Dwelling27106022215
Maisonette53736128,480
House187055336,575
Detached house1570762221,426
Semi-detached house4937661219,591
End of terrace house602396160,802
Mid-terrace house61221061117,832
       
Total40381552807,067
Table 11 Average Floor Area by Period of Construction and Type of Dwelling (2009-2019)
m2
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-18996853455651105149158148116106119
1900-19296450435442891191241219790100
1930-1949516245515074111120111858298
1950-19667064555655681161261148886104
1967-197767656055101651321391098584110
1978-19826367645610068138142978482110
1983-1993585955585771147149968381109
1994-19996663586758761531611028483111
2000-20047471697769881671771049692115
2005-200981727179899417119110610198112
2010-20148478717686101195214122117110142
2015-20198082848881111187196126122116131
 
All7667667158861481561069389111
Table 12 Average Primary Energy Use by Period of Construction and Type of Dwelling (2009-2019)
kWh/m2/year
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-1899434420383481409469417408377415364399
1900-1929479428427494394455413419382414373405
1930-1949363348280422458431374397341360322359
1950-1966415326284383519319336352305333298323
1967-1977384310254354319312289298282281254285
1978-1982333283238290309303244251253245221248
1983-1993346297252296337276227233241244222237
1994-1999283273236275278250206207225246223221
2000-2004254237203236260207188191209214191202
2005-2009170187161190179163151161174170156167
2010-201420511295118132941009883888494
2015-20191036149596360575655555155
             
All221243192251327226232238229248244235
Table 13 Average Carbon Dioxide Emissions by Period of Construction and Type of Dwelling (2009-2019)
kgCO/m2/year
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-189910295831088610910710591998598
1900-1929114979311086108107109929887100
1930-194985806092101989610280837487
1950-19669972608211368858969756776
1967-1977926953767771737465655968
1978-1982806450637771616360565160
1983-1993836755668262565856565057
1994-1999666052606355505052565052
2000-2004585144505644464648474147
2005-2009363934403533363840373438
2010-2014462318233019232317181721
2015-201920129111212121211101011
 
All505341547149585953565556
Table 14 Dwellings with Multiple BER Ratings (2009-2019)
                 % of total
Earliest YearLatest YearTotal
A1A2A3B1B2B3C1C2C3D1D2E1E2FG
A1000
A20000
A30000000
B100000000000
B20000000000001
B3000012100000004
C10000023100000007
C20000233100000010
C300000133210000012
D100000123321000014
D200000122232100013
E10000011112210009
E20000011111111008
F0000011111111109
G00000111111111212
 
Total00114131816131295332100
– No dwelling received this BER rating combination for the earliest and latest assessments
Table 15 BER Ratings Weighted to National Level (2009-2019)
             % of row  
Dwelling TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Apartment426911111011117558164,387
Detached house2127101213121165611675,709
Semi-detached house311510141515127665434,400
Terraced house211610121212128779262,542
               
Total3126101213131276691,537,038

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 817,916 unique domestic BERs (one per dwelling) completed in the period 2009 to the end of March 2019. 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 2009-2019 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 March 2019; 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 8-10. 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 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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