Energy rating of housing in Northern Ireland
Up to March
2023
Coverage: Northern Ireland
Frequency: Annual
Publication
Date: 10 July 2024
Main points
Dwellings in Northern Ireland with a valid Energy Performance
Certificate (EPC) had a median energy rating in band D, with a score of
65.
Flats and maisonettes were the property type in Northern Ireland
with the highest median energy rating with a score of 74, equivalent to
band C.
Social dwellings had a median energy rating certified at band D
in most of the local government districts, apart from Belfast and Antrim
and Newtownabbey which had median energy ratings certified at band
C.
In Northern Ireland, approximately four in ten (39%) dwellings
with a valid EPC had an energy rating band at C or above.
Of all dwellings built before 1930 in Northern Ireland,
approximately 90% were rated in bands D to G.
Over nine in ten dwellings used either gas or oil as a main fuel
source for heating in each local government district.
Section 1: Energy rating in Northern Ireland
Several factors affect the energy rating of a dwelling, including
property type and when or how it was constructed. This bulletin
highlights the types of dwellings typically associated with high and low
energy rating scores.
Energy Performance Certificates (EPCs) indicate the energy rating
(based on running costs) and environmental impact of dwellings along
with improvement recommendations, if applicable. They are based on data
about a building’s energy features, for example, levels of insulation,
efficiency of heating systems and the inclusion of renewable energy
generation technologies, as well as standardised assumptions for
occupancy and behaviour. They are collected by an accredited energy
assessor and entered into government-approved software to generate an
EPC score, typically ranging from 1 to 100. Domestic EPCs are rated from
A to G, where A is likely to result in lower energy bills.
The scores associated with each energy rating band are:
- band A - 92 plus (most efficient in terms of running cost)
- band B - 81 to 91
- band C - 69 to 80
- band D - 55 to 68
- band E - 39 to 54
- band F - 21 to 38
- band G - 1 to 20 (least efficient in terms of running cost)
This analysis uses EPC data to present energy rating, the main fuel
type used in heating, and the carbon dioxide (CO2) emissions of
dwellings with an EPC for Northern Ireland. It is based on one record
per dwelling, using records from April 2013 to March 2023. This is
because EPC’s are only valid for 10 years from when dwellings are
constructed, converted, sold or let.
More information on the base population can be found in Data
sources and quality.
Energy rating by region
The median energy rating score for Northern Ireland was 65 for all
records in the ten year period to March 2023, which is equivalent to
band D. Analysis by local government district shows that although there
is some variation in the average energy rating score, the average score
for each LGD falls into band D. Causeway Coast and Glens had the lowest
median score (61), while Belfast had the highest median score of 68.
Energy rating by property type and tenure
Energy rating varies by property type. Overall, flats and maisonettes
were the property type in Northern Ireland with the highest median
energy rating, with a score of 74, which is equivalent to band C (see
Figure 2). Flats and maisonettes are the only property type that had a
score above band D.
Detached dwellings had the lowest median energy rating score of
property types in Northern Ireland (60). This may be a result of
external wall exposure being higher in houses, compared with flats and
maisonettes which are more likely to be grouped in blocks. While there
was a larger difference in energy rating between flats and houses, there
was a smaller difference between the different types of houses.
Energy rating by property age
The age of a dwelling tends to affect the energy rating, as building
techniques and regulations have changed over time, in addition to the
effects of ordinary use and aging. Dwellings constructed after 2014 had
a median energy rating score equivalent to band B, 83 in Northern
Ireland (Figure 4). In contrast, dwellings constructed before 1930 had a
median score of 51, which is equivalent to band E.
Energy rating for new and existing dwellings
As at March 2023, there were approximately 319,000 unique valid
entries on the EPC register. The properties covered by the EPC register
are a mix of newly built or converted dwellings and existing properties
being issued with a first or updated EPC. New and existing dwellings are
assessed using slightly different methodologies (the standard
assessment procedure and the reduced standard assessment
procedure).
The median energy rating score for new and existing buildings can
differ because of the use of modern techniques and materials in the
building of newer properties. The median energy rating score for new
dwellings in Northern Ireland was equivalent to band B (83), compared
with the score for existing dwellings that was equivalent to band D
(62).
The median energy rating score for new properties in Northern Ireland
were similar across all housing types, ranging from 82 to 83 (Figure 5).
However, as existing dwellings make up the majority of the EPC records
analysed in Northern Ireland (83%), the energy rating patterns shown in
the existing dwellings have a greater impact on the overall figures for
all dwellings.
Section 2: Individual EPC bands
When looking at all dwellings in Northern Ireland, approximately
two-fifths (39%) of dwellings achieved an energy rating of C or above.
However, the most common rating in Northern Ireland was a rating of D
(35%).
Three-quarters (75%) of new dwellings achieved a band B and 23%
achieved a band C rating. In contrast, only 1% of existing dwellings had
a rating in band B. Most existing dwellings were in bands C and D; 26%
in band C, and 42% in band D.
Looking at age of property for individual EPC bands, dwellings built
before 1930 were most commonly rated in band D (33%) and E (30%) (Figure
8). In fact, 90% of all dwellings in Northern Ireland built before 1930
were rated in bands D to G. For dwellings constructed after 2014, band B
was the most common rating, with 79% of such dwellings in Northern
Ireland.
Section 3: Heating fuel type for dwellings
One of the main contributors to energy use in the home is space and
water heating, with different sources of heating seen as more or less
energy efficient. As part of the Energy Performance Certificate (EPC)
assessment, the main fuel type of heating is recorded. The analysis
presented below focuses on the fuel type that directly powers a
dwelling’s heating. This means that someone who is on a 100% renewable
tariff for their electricity will be categorised as using electricity as
their heating fuel type rather than renewable energy. If there was no
heating record, for this analysis we group these dwellings in the
“others/none” category.
As of March 2023, 53% of dwellings in Northern Ireland with an EPC
used oil for their heating. Gas was the second most common fuel type for
heating (42%). All other fuel types make up just 5% of fuel used in
heating in dwellings in Northern Ireland.
Among local government districts, Belfast had the highest proportion
of homes that used gas to fuel their heating (78%). In contrast, 89% of
dwellings in Mid Ulster used oil to fuel their heating.
Figure 8: Main fuel type used in heating, by local
government districts, April 2013 - March 2023
Section 4: Carbon dioxide emissions
Energy Performance Certificate (EPC) data on estimated carbon dioxide
(CO2) emissions are based on standardised assumptions about how
residents will use the dwelling (such as number of occupants, heating
patterns and hot water usage).
Section 5: Representativeness of dwellings covered by an EPC
To analyse the representativeness of dwellings covered by Energy
Performance Certificates (EPCs), the EPC data was compared with the
Housing Stock statistics published by Land and Property Services (LPS)
in June of each year.
As of March 2023, around 39% of all residential dwellings in Northern
Ireland had a valid EPC registered in the previous 10 year period.
Across local government districts (LGDs) there was some variation in the
proportion of housing stock with a valid EPC, with almost half (48%) of
homes in Belfast having a valid EPC while in Fermanagh and Omagh the
comparable figure was 29%.
Analysis by property type indicated that flats and maisonettes had
the highest coverage (53%), while detached houses had the lowest
coverage (27%).
Glossary
Dwelling
A dwelling is an address containing a unit of accommodation that can
comprise one or more household spaces.
Energy efficiency
Energy efficiency relates to the concept of efficient energy use,
which means using less energy to provide a given amount of heating or
lighting. Using less energy reduces emissions of carbon dioxide,
although there can be exceptions. For example, using bio fuels will
reduce the carbon emissions but is likely to lead to higher running
costs and therefore lower energy efficiencies.
Energy rating
The energy rating and score is a measure of the overall efficiency of
a dwelling reflecting its modelled running cost/m2/annum. This score is
based on the modelled performance of the building and its fixed services
for heating, cooling, ventilation, lighting and any ancillary power
needed to service these functions. It does not include other ancillary
uses, such as general power for day-to-day appliances or cooking. The
higher the score, the more cost-efficient the home. The score is
produced during an Energy Performance Certificate (EPC) assessment and
is based on standardised assumptions for occupancy and behaviour.
Energy Performance Certificate
Energy Performance Certificates (EPCs) are required for all buildings
(domestic and non-domestic), when constructed, sold or rented. There are
some exemptions, for example for buildings used as places of worship.
EPCs are valid for 10 years. The EPC records how energy efficient a
property is as a building. The EPC uses an A-to-G rating scale, where A
is the most efficient and G is the least efficient.
Existing dwelling
Statistics for existing dwellings were created using data from the
latest EPC record available for existing dwellings in the past 10 years.
Existing dwellings are those that are required to undergo an energy
performance assessment as they are either being sold or let and are not
newly constructed or converted.
New dwelling
Statistics for new dwellings are generated using data from new
dwelling EPC records. A new dwelling is any dwelling that has been newly
constructed, created by conversion or has undergone a change of use and
is now required to have an energy performance assessment.
Standard assessment procedure (SAP)/Reduced standard
assessment procedure (RdSAP)
The SAP software for new dwellings is significantly more detailed
than RdSAP and would be considered more robust. RdSAP EPCs are designed
to be non invasive, and to be carried out on existing buildings where
the exact make and model of every material that has gone into the build
may not be available. Instead of using precisely calculated thermal
performance data for each element, the RdSAP software makes an
assumption based on the construction date of the property.
Data Sources and quality
Interpreting these statistics
The analysis in this article does not cover all dwellings in Northern
Ireland because not every dwelling has an EPC (as these are only
required when a dwelling is constructed, converted, sold or let). EPCs
are valid for 10 years, so do not necessarily reflect energy efficiency
improvements. Dwellings can have more than one record, but only the
latest record was included in the analysis, so dwellings are not double
counted in any time period analysed.
Some dwellings included in the statistics may have changed tenure
since the date of their latest EPC. For instance, dwellings that had an
EPC for reasons other than being let may have since entered the private
or social rented sector.
Official Statistics in development
Official
statistics in development (previously called Experimental
Statistics) are official statistics that are undergoing a development,
and may be new or existing official statistics. They are published to
involve users and stakeholders in their development and as a means to
ensure they will meet user needs going forward. As these statistics are
still in development, they are subject to retrospective revision in any
future releases. The methodology and quality assurance are still in
development and are subject to change.
These official statistics are produced in compliance with the Code of
Practice for Statistics.
Feedback on these statistics is particularly welcome from users and
will be used to further develop the statistics. You are able to give
feedback on our user
engagement survey.
Our statistical practice is regulated by the Office for Statistics
Regulation (OSR). OSR sets the standards of trustworthiness, quality and
value in the Code of Practice for Statistics that all producers of
official statistics should adhere to. You are welcome to contact us
directly with any comments about how we meet these standards by emailing
analyticsdivision@communities-ni.gov.uk.
Alternatively, you can contact OSR by emailing regulation@statistics.gov.uk or
via the OSR
website.
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