A quarter of all energy used in Ireland is consumed directly in homes. Second only to transport, and more than is used by industry.

Significant energy use of the residential sector

The residential sector accounts for a quarter of the energy used in Ireland. It is also responsible for a quarter of the energy-related CO2 emissions. From 2006 to 2014 there were significant reductions in the amount of emissions from homes. After 2014 this trend has reversed somewhat, with carbon dioxide emissions increasing in 2015 and 2016, though they reduced again in 2017.

The graphs below show trends in energy use in homes, broken down in different ways.

Final residential energy demand

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Residential Final Energy (ktoe),Residential Final Energy Demand,Weather Corrected Residential Final Energy Demand
Source: SEAI

Adjusting for weather

Weather variations from year to year affect energy demand, particularly for space heating. It is useful to adjust for annual weather variations by using degree-days.

Return to growth

Weather corrected residential energy demand decreased every year between 2007 and 2012, but grew in 2013, 2015 and 2016. Between 2014 and 2016, residential sector final energy consumption increased by 6.5% (3.2% per annum). In 2017 energy demand decreased, due mostly to it being a milder year. When corrected for weather growth in energy was flat.

Reasons for changes

Potential reasons for the decrease in household energy use between 2007 and 2014 include:

  • Improved thermal efficiency due to retrofitting and building regulations
  • Reduced household incomes and expenditure, due to the economic downturn
  • High energy prices

Potential reasons for the increase between 2014 and 2016 include:

  • Increasing household incomes and expenditure
  • Reduced energy prices, particularly of oil

Final residential energy demand by fuel type

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Residential Final Energy by fuel (ktoe),Coal,Peat,Oil,Natural Gas,Renewables,Electricity
Source: SEAI

Dominance of oil

Oil has remained the largest fuel source since 2000. It accounted for 37% of all final energy used in the residential sector in 2017. The next largest source was electricity at 26%.

Between 1990 and 2000 there was a clear switch away from solid fuels used in open fires towards oil and gas central heating systems. After 2000, fuel shares became more stable. We can see a gradual increase in shares of electricity and gas and a continuing decline in coal and peat use.

Weather corrected oil and gas use

Changes in oil use were the main source of fluctuation in overall household energy demand between 2007 and 2016. Weather corrected oil use declined by 28% between 2007 and 2014, increased by 17% between 2014 and 2016. In comparison weather corrected gas demand decreased by 17% between 2007 and 2014 and increased by 5% between 2014 and 2016. In 2017 oils and gas decreased by 4% and 1% respectively.

A likely reason for the higher fluctuation in oil use may be the greater fluctuation in oil prices. Additionally, the majority of oil-fired dwellings are in rural areas. These areas may offer greater opportunity for fuel switching to solid fuels.


Total electricity consumption peaked in 2008. It reduced slightly between 2008 and 2017, having more than doubled between 1990 and 2008. There is evidence that the growth of large household appliances is levelling off. At the same time, there has been an increase in appliance efficiency. Additionally, there was an increase in electricity prices over the period.


Between 2005 to 2017 renewable energy grew by 220% from a low starting point. New building regulations require new dwellings to generate a portion of their energy from renewable energy, and this has seen a large increase in the use of solar thermal water heating, solar PV electricity, and heat pumps which provide renewable ambient energy.

Final energy by end-use

Electricity,Space heating,62.21
Electricity,Water heating,80.82
Electricity,Lighting and appliances,467.96
Electricity,Other end uses,25.44
Gas,Space heating,388.96
Gas,Water heating,152.59
Gas,Lighting and appliances,0
Gas,Other end uses,0
Solid Fuels,Space heating,308.28
Solid Fuels,Water heating,32.54
Solid Fuels,Cooking,0
Solid Fuels,Lighting and appliances,0
Solid Fuels,Other end uses,0
Oil,Space heating,736.79
Oil,Water heating,225.78
Oil,Lighting and appliances,0
Oil,Other end uses,0
Renewables,Space heating,39.24
Renewables,Water heating,24.05
Renewables,Lighting and appliances,0
Renewables,Other end uses,0
Source: SEAI

Challenge of gathering end-use data

It's important for us to understand how energy is consumed in homes. In particular, we need information on the portion of energy consumed for the main end-uses. These include space heating, water heating, cooking, lighting and electric appliances.

We cannot collect data on energy by end-use in the same way as it is by fuel type. For example, it's not possible to use electricity meter data to tell the share used for water heating.

A new model for estimation

To estimate the split, SEAI developed a model of household energy consumption. We based it on data from the BER database. For 2017 we estimate that 59% of all energy used in households was for space heating, 20% for water heating, 18% for lighting & appliances, and 2% for cooking.

Energy related CO₂ emissions

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Residential Carbon Emissions (ktCO2),Coal,Peat,Oil,Natural Gas,Electricity
Source: SEAI

Second highest source of CO2

The residential sector accounted for 24% of energy-related CO2 emissions in 2017. This includes upstream electricity emissions. The residential sector was the second largest source of CO2 emissions after transport (which accounted for 39%), and was ahead of industry.

The trend for residential energy-related CO2 emissions mostly follows the trend in energy consumption. Residential energy related CO2 emissions increased in decreased in 2017, having increased in 2015 and 2016.

CO2 emissions by fuel source

The graph shows residential energy related CO2 emissions split by fuel source. Oil, gas, coal and peat are burned directly within the home. We also factor in CO2 emissions from electricity generating stations producing electricity for homes.

The emissions from electricity use in the home are the largest source of emissions by fuel type. They accounted for 38% of total residential CO2 emissions in 2017. Oil use was the next largest source, accounting for 32%. If we exclude electricity, oil accounted for 52% of residential CO2 emissions from direct fuel use in homes.

Final energy per dwelling

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Energy intensity per dwelling,Non-electric energy,Non-electric (Weather corrected),Electricity
Source: SEAI

In 2017 the average dwelling consumed a total of 17.8 MWh of energy – 74% from direct fuel use and 26% from electricity. Weather corrected final energy use per dwelling remained constant between 2000 and 2005. It fell by 29% between 2005 and 2014, but has been more or less flat from 2014 to 2017.

Energy related CO₂ emissions per dwelling

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CO2 emissions per dwelling,Total energy-related CO2  per dwelling,Non-electrical energy-related CO2 per dwelling,Electricity energy-related CO2  per dwelling
Source: SEAI

Overall energy related CO₂ emissions

In 2016 the average dwelling emitted 5.3 tonnes of energy-related CO2. 62% of these were from direct fuel use in the home and 38% indirectly from electricity use.

The emissions of energy-related CO2 per dwelling fell by 36% between 2005 and 2017. This compares to a reduction in energy per dwelling of 26%). Emissions from energy use in households decreased 7% in 2017. This is mainly a result of milder weather throughout the year.

Fuel use

Energy related CO2 emissions per dwelling for non-electric fuel use fell by 34% between 2005 and 2017. This is primarily a result of reduced energy consumption per dwelling.

Electricity use

CO2 emissions from electricity use reduced by 40% in the same period. This is due to reduced electricity use and reduced carbon intensity of the electricity grid.

SEAI National BER research tool

The BER Research Tool gives researchers access to statistical data from the Building Energy Rating (BER) scheme which is administered by SEAI. The BER certificate indicates the annual primary energy usage and carbon dioxide emissions associated with the provision of space heating, water heating, ventilation and lighting to the dwelling. This tool provides access to information on all aspects of construction that affect the energy performance of dwellings. Results can be viewed on screen or downloaded in the form of a Microsoft Excel spreadsheet.

Go to National BER research tool

Energy in the Residential Sector report

Our Energy in the Residential Sector 2018 report provides detailed data and analysis. It also offers a comparison of Irish homes to those of other EU countries.

Go to latest Energy in the Residential Sector report