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

Residential sector has a large share of energy use

The residential sector accounts for about 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 energy used in homes and the resulting CO2 emissions. After 2014 this trend has reversed somewhat, correcting for weather, energy use in households was 9% higher in 2018 than in 2014. Despite the increase in energy use, CO2 emissions reduced slightly between 2016 and 2018, this was because electricity has become less carbon intensive.

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, which we can do using the method of degree-days.

Return to growth

Weather corrected household energy demand decreased between 2007 and 2014, but has increased in every year since, with the exception of 2017. Between 2014 and 2018, weather corrected household final energy consumption increased by 9%.

In 2018 we had storm Emma, which brought snow and cold temperatures to all parts of the country, but over the full year, on average, it was just a little colder than the previous year. Actual household enregy use increased by 7% in 2018. When we corect for weather, the increase was still 5%.

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 2018 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 40% of all final energy used in the residential sector in 2018. The next largest source was electricity at 25%.

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 2018. Weather corrected oil use declined by 28% between 2007 and 2014, increased by 22% between 2014 and 2018. In comparison weather corrected gas demand decreased by 17% between 2007 and 2014 and increased by 11% between 2014 and 2018. In 2018 oil and gas increased by 8% and 7% 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, having more than doubled since 1990. It reduced between 2008 and 2014, but returned to growth from 2014 to 2018. 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 2018 renewable energy grew by over 200%, but 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,68.06
Electricity,Water heating,82.45
Electricity,Lighting and appliances,477.47
Electricity,Other end uses,25.96
Gas,Space heating,431.82
Gas,Water heating,157.85
Gas,Lighting and appliances,0
Gas,Other end uses,0
Solid Fuels,Space heating,323.24
Solid Fuels,Water heating,31.99
Solid Fuels,Cooking,0
Solid Fuels,Lighting and appliances,0
Solid Fuels,Other end uses,0
Oil,Space heating,819.68
Oil,Water heating,234.87
Oil,Lighting and appliances,0
Oil,Other end uses,0
Renewables,Space heating,43.24
Renewables,Water heating,25.14
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 is useful to know the portion of energy consumed for the main end-uses. These include space heating, water heating, cooking, lighting and electric appliances. For 2018 we estimate that 61% of all energy used in households was for space heating, 19% for water heating, 17% for lighting & appliances, and 2% for cooking.

We cannot collect data on energy by end-use in the same way as for fuel use. For example, it's not possible to know from an electricity meter reading how much electricity is used for for water heating versus appliances. To estimate the split, SEAI developed a model of household energy use based on information from the BER database.

Energy related CO₂ emissions

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Residential Carbon Emissions (ktCO?),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 2018. This includes upstream electricity emissions. The residential sector was the second largest source of CO2 emissions after transport (which accounted for 40%), and was ahead of industry.

The trend for residential energy-related CO2 emissions mostly follows the trend in energy consumption. CO2 emissions from households increased between 2014 and 2016 but decreased in 2017. 2018 was unusual because CO2 emissions stayed flat even though energy use went up. This was becuase of a reduction in the CO2 intensity of electricity.

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.

CO2 emissions from electricity were the largest source of CO2 emissions from households from 1990 up to 2017, but in 2018 they were surpassed by the CO2 emissions from oil use. Electricity and oil accounted for 34% and 35% of CO2 emissions from households in 2018, respectively.

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 2018 the average dwelling consumed a total of 18.6 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 increased by 7% from 2014 to 2018.

Energy related CO₂ emissions per dwelling

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

Overall energy related CO₂ emissions

In 2018 the average dwelling emitted 5.2 tonnes of energy-related CO2. 66% of these were from direct fuel use in the home and 34% indirectly from electricity use.

The emissions of energy-related CO2 per dwelling fell by 38% between 2005 and 2018. This compares to a reduction in energy per dwelling of 24%). Emissions from energy use in households remained flat in 2018, despite an increase in energy use. This is a result of a reduction in the CO2 intensitey of electricity.

Fuel use

Energy related CO2 emissions per dwelling for non-electric fuel use fell by 33% between 2005 and 2014, but increased by 6% from 2014 to 2018. This is due to changes in fossil fuel use, in particular oil.

Electricity use

CO2 emissions from electricity per dwelling 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