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For more information on this release:
E-mail: environment@cso.ie Dympna Corry (+353) 1 4984207 Linh Nolan (+353) 1 4984209
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, , 11am

Domestic Building Energy Ratings

Quarter 3 2018

Table A: BER Ratings by Period of Construction
% of row
Period of constructionEnergy rating 
ABCDEF-GTotal
1700-19770418252033240,652
1978-1999054036136229,977
2000-200409602372143,009
2005-2009135511031136,216
2010-20143655710010,734
2015-2018963000025,072

96% of Dwellings built in 2015-2018 were given an "A" rating

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

Dwellings built in 2015-2018 were considerably more energy efficient than in earlier periods with 96% given an “A” rating compared with 36% in 2010-2014 and 1% in 2005-2009 (see Table A and Figure 1).

There was a decrease of 2.5% in the number of dwellings receiving a BER audit in the first three quarters of 2018 compared with the same period in 2017 (see Table 1).

Dublin County had the highest combined “A” and “B” rating at 25% (see Table 4). Offaly 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 40% (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 27% than in Dublin 18. The highest proportion of combined “F” and “G” rating was 27% for Dublin 7.

Mains gas was the main space heating fuel used in 57% of the 23,465 dwellings completed during 2015-2018 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 6% for dwellings built in 2015-2018. In contrast usage of electricity increased from 19% in 2000-2004 to 36% in 2015-2018 (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 59 square metres for basement dwellings.

EarliestLatest
A01
B101
B214
B3412
C1718
C21016
C31213
D11412
D2139
E1105
E283
F93
G122
EarliestLatest
A00
B101
B214
B3412
C1717
C2916
C31213
D11412
D2149
E1105
E283
F93
G122
National DataBER Database
A24
B111
B223
B367
C11011
C21213
C31313
D11313
D21211
E177
E265
F65
G97
National DataBER database
A23
B111
B223
B367
C11011
C21213
C31313
D11313
D21211
E177
E265
F65
G97
Table 1 Domestic Building Energy Ratings Certificates (2009-2018) 1
number
Period2009201020112012201320142015201620172018Total
January4,1024,6768,5666,5286,9687,0066,5235,2565,6865,22860,539
February6,3225,6239,0256,3108,5277,5417,6606,8656,8106,54971,232
March8,7696,1598,9436,5148,2088,3857,2627,5387,6276,57175,976
April8,0415,4807,7794,4428,2998,7347,5907,3927,1347,10972,000
May7,9265,4738,8775,8748,6458,7287,7177,9548,1798,51177,884
June8,7325,7817,4644,8627,2638,2178,0017,4467,6897,71573,170
July8,7755,9657,2585,5357,0969,3967,6746,5607,1227,65173,032
August7,2696,4317,5325,0456,9748,1647,6487,0287,2517,22470,566
September7,5197,4308,8534,9738,2829,9208,3577,6737,9727,28578,264
October6,5898,4049,5676,6918,97910,7719,2217,9328,065 76,219
November6,97011,6119,6198,8039,60310,8998,4129,0238,396 83,336
December6,3418,0149,4756,3656,9367,7787,3116,0795,684 63,983
            
Total87,35581,047102,95871,94295,780105,53993,37686,74687,61563,843876,201
1 Includes all Certificates for Dwellings
Table 2 BER Ratings by Period of Construction (2009-2018)
% of row 
Period of ConstructionEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
1700-18990012234710910143820,398
1900-19290012234710910143743,707
1930-194900134579121010132638,392
1950-1966001356811141111131760,054
1967-19770013681115171199878,101
1978-198200148131518181065351,693
1983-19930014913162018854385,717
1994-199900151015192014643192,567
2000-200400171622211484321143,009
2005-200913102124189642110136,216
2010-20143629161042110000010,734
2015-2018962100000000025,072
               
Total413711131313117557785,660
– No dwelling received this BER rating for this period of construction
Table 3 BER Ratings by Type of Dwelling (2009-2018)
% of row 
Dwelling TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Apartment14111312710101065564,291
Ground-floor apartment213710111012131076744,012
Mid-floor apartment451012121211118433352,946
Top-floor apartment2148109912149651045,489
Basement Dwelling1325478711101032226
Maisonette12711131110101264488,243
House12491214141311544836,917
Detached house3127111313131165610212,268
Semi-detached house611511151515116554209,737
End of terrace house51151013121211767958,157
Mid-terrace house412813131111117668113,374
               
Total413711131313117557785,660
– No dwelling received this BER rating for this dwelling type
Table 4 BER Ratings by County (2009-2018)
% of row  
CountyEnergy Rating Average age
AB1B2B3C1C2C3D1D2E1E2FGTotal
Carlow21261215141511655710,72329
Dublin 01-24524710111113127667174,61736
Dublin County122481113121210544457,08527
Kildare81271214141310543532,05724
Kilkenny11271213131312755912,74135
Laois1129111514129666912,10229
Longford0227121212151165796,69628
Louth4238161513129544621,65832
Meath9138141613118433526,55224
Offaly11249131211119891110,53534
Westmeath112710131514116661014,58931
Wexford21251014151512755825,97929
Wicklow51271112121311755822,32633
Clare1126913151412765821,10432
Cork City21481212111211866721,23945
Cork County31411151412119544769,72732
Kerry11371112131412755825,90029
Limerick City21141214151513755712,91736
Limerick County20261114151413655722,76632
Tipperary11159121314128671126,24539
Waterford City3125121314161375458,46835
Waterford County31261213131412645712,46135
Galway City2125912161714755411,94624
Galway County11271114151311755832,36128
Leitrim00261214131110667125,98731
Mayo21259131514136561021,09232
Roscommon10151115151210756129,50832
Sligo11271012131313866912,85731
Cavan1138151612129655911,84928
Donegal11261315141311655823,95229
Monaghan2138121112141275587,62135
                
Total413711131313117557785,66032
Table 5 BER Ratings by Dublin Postal District (2009-2018)
% of row  
Dublin Postal DistrictEnergy Rating Average age
AB1B2B3C1C2C3D1D2E1E2FGTotal
Dublin 1226791011131386587,24031
Dublin 2336681112131186574,12935
Dublin 3203688911129910137,29355
Dublin 4114791010131397779,16344
Dublin 51125810111513109867,30743
Dublin 641346781113989167,68758
Dublin 6W4126881012129910104,10250
Dublin 7101369912131010111610,09857
Dublin 81258891012138781112,27845
Dublin 940368109111398998,97946
Dublin 10125131512121187873,25344
Dublin 115271212111111965549,73030
Dublin 12212468101213101012118,56253
Dublin 13131410101110111065436,11228
Dublin 1453588910111397768,27337
Dublin 151124101315131310422118,09417
Dublin 167148111312141264427,58328
Dublin 17516914191413842214,00924
Dublin 18771115151299732218,92017
Dublin 208379778121396542,05530
Dublin 22201491415181895336,19227
Dublin 2461251215141513754213,55822
                
Total524710111113127667174,61736
– No dwelling received this BER rating in this postal district
Table 6 BER Ratings by Main Space Heating Fuel (2009-2018)
% of row  
Fuel TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Mains Gas524101515131295432307,231
Bulk LPG2261621181396322111,220
Bottled LPG113814151112125459948
Heating Oil112612151615126555297,929
Electricity81113681316118716116,893
Coal00011412141419353,417
Smokeless Fuel00001412151417375,545
Peat0011311131217421,459
Wood Pellets & Chips3611201315107532321,326
Wood Logs42232349139101030605
Solid Multi-Fuel00000127131414163428,931
               
Total313711131313117557775,504
– No dwelling received this BER rating for this main space heating fuel type
Table 7 BER Ratings by Main Water Heating Fuel (2009-2018)
             % of row 
Fuel TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Mains Gas524101515131295432305,479
Bulk LPG2261721181396322111,174
Bottled LPG0039141512111164591,045
Heating Oil112612151615126555295,560
Electricity81113681315108718123,088
Coal0001112513151619273,301
Smokeless Fuel0011414161519294,908
Peat0011411131317401,486
Wood Pellets & Chips3611201315117532321,318
Wood Logs321333511131091126560
Solid Multi-Fuel00000127141414173027,585
               
Total313711131313117557775,504
– No dwelling received this BER rating for this main water heating fuel type
Table 8 Main Space Heating Fuel by County (2009-2018)
% of row    
CountyFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
Carlow3546116210,715
Dublin 01-247362010168,942
Dublin County7612111055,204
Kildare4837123131,942
Kilkenny295198212,684
Laois3145815112,075
Longford262201336,631
Louth563462121,409
Meath4640103126,530
Offaly10551024110,415
Westmeath14541513314,534
Wexford1701511325,870
Wicklow4340115122,214
Clare13591511321,061
Cork City739162021,092
Cork County3941144269,354
Kerry1642010525,759
Limerick City5520214012,784
Limerick County2849148122,695
Tipperary14641011126,165
Waterford City631420308,445
Waterford County2154176212,404
Galway City2040335211,860
Galway County767167332,266
Leitrim066161265,985
Mayo373148321,050
Roscommon471121039,507
Sligo163219512,836
Cavan968118511,767
Donegal08196423,722
Monaghan9739737,587
 
Total40381552775,504
Table 9 Main Space Heating Fuel by Period of Construction (2009-2018)
% of row  
Period of ConstructionFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
1700-18992938229119,923
1900-192930402010143,103
1930-1949433899138,291
1950-1966474066159,886
1967-1977385047177,485
1978-1982365248151,459
1983-19933446117285,239
1994-19993338235191,993
2000-200440361942142,189
2005-200946301824132,469
2010-20145526151210,002
2015-2018576360123,465
       
Total40381552775,504
Table 10 Main Space Heating Fuel by Type of Dwelling (2009-2018)
% of row 
Dwelling TypeFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
Apartment46447124,038
Ground-floor apartment477431241,950
Mid-floor apartment401580148,494
Top-floor apartment413531243,309
Basement Dwelling26106121203
Maisonette53736128,138
House187055336,897
Detached house1570662212,102
Semi-detached house4838671209,432
End of terrace house602497157,954
Mid-terrace house61221071112,987
       
Total40381552775,504
Table 11 Average Floor Area by Period of Construction and Type of Dwelling (2009-2018)
m2
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-18996854455652105149158148116105119
1900-19296451435443891191241219790100
1930-1949516245515075110120110858298
1950-19667064545658671161251148886104
1967-197767655956101651321391098584109
1978-19826266645510068137142978482110
1983-1993585955585771147149968281109
1994-19996663586759761531611018483111
2000-20047471697768881661771039592115
2005-200981727179909417119110610198111
2010-20148478717686101195214122117109142
2015-2018808281870117187196126123118133
             
All7667667059861481561069289111
Table 12 Average Primary Energy Use by Period of Construction and Type of Dwelling (2009-2018)
kWh/m2/year
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-1899434420384483415472417409379417365400
1900-1929480426429496392449412421383416374407
1930-1949363348282423458441375400343363325362
1950-1966415329290389515318336354306336300325
1967-1977385311255357319312289299283282255287
1978-1982336283239290309304245252254246222249
1983-1993346298253297337276228233242245223238
1994-1999285274237276276252206207227247224222
2000-2004253238204237268208189192211216192204
2005-2009170188161191179163151162175171157168
2010-201420511194117132921009883888494
2015-2018103625059066575655555155
             
All222245194253329229232240232252247238
Table 13 Average Carbon Dioxide Emissions by Period of Construction and Type of Dwelling (2009-2018)
kgCO/m2/year
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-1899102958310988110107106911008598
1900-1929114979411086106107110929987100
1930-1949857960931011019610381847588
1950-19669973628411368858969766877
1967-1977927053777771737465655968
1978-1982816451637772616360575160
1983-1993836755668262565856575157
1994-1999676152616255505052565052
2000-2004585144515844464649474247
2005-2009363934403534363841373438
2010-2014462318233018232317181721
2015-20182012911013121211101011
             
All505441557150586054575656
Table 14 Dwellings with Multiple BER Ratings (2009-2018)
                 % of total
Earliest YearLatest YearTotal
A1A2A3B1B2B3C1C2C3D1D2E1E2FG
A1000
A20000
A30000000
B10000000000
B20000000000001
B3000012100000004
C1000023100000007
C20000232100000010
C300000133210000012
D10000123321000014
D20000122232100013
E10000111122100010
E2000011111111008
F000011111111109
G0000111111111212
                 
Total00114121816131295332100
– No dwelling received this BER rating combination for the earliest and latest assessments
Table 15 BER Ratings Weighted to National Level (2009-2018)
             % of row  
Dwelling TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Apartment326911111011117558164,544
Detached house2127101213131165612675,655
Semi-detached house211510141515137665434,352
Terraced house2116101212121287710262,667
               
Total2126101213131276691,537,218

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 785,660 unique domestic BERs (one per dwelling) completed in the period 2009 to the end of September 2018. 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 2009-2018 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 2018; 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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