CAR wrote the UK Housing Energy Fact File for the Government’s Department of Energy & Climate Change (now Department for Business, Energy and Industrial Strategy). This replaced the Domestic Energy Fact File, commonly known as the bible for housing energy data.

We extended and revised the Fact File through three editions. The 2013 Fact File covered the period from 1970 to 2012, and it drew together all of the important data about energy use in homes in the UK. It was intended for policy-makers, researchers, and interested members of the public, and considered the relationship between domestic energy use and carbon dioxide emissions.

The energy we use in homes accounts for more than a quarter of UK energy use. CO₂ emissions from housing are down by 25% compared to 1970, but if we are to meet the Government target for cutting greenhouse gas emissions by four-fifths by 2050, we have to think carefully about how we use energy in our homes.

Our modelling work showed that the average temperature of homes in winter has increased by 4 degrees since 1970. This is an average in time (day and night/occupied and unoccupied) and space (most households now heat most rooms, whereas they typically only the living room in 1970). Some homes have witnessed a bigger jump, while some poorer households are scarcely any warmer than they were.

The average increase in winter temperatures has come at the expense of greater energy use, and we now use a third more energy for heating than in 1970. However, far more efficient heating systems, married to better insulation for most homes, offset what would have been a much bigger hike in energy use.

The remarkable finding from the Fact File was that in spite of a vast increase in energy services in homes (microwaves, dishwashers, freezers, mobile phones and computers), CO₂ emissions per household fell by almost half over four decades: from 9.6 tonnes per household to 5.0. (Emissions have continued to fall since.) We used time series data generated with CAR’s Cambridge Housing Model to produce a breakdown of energy use for different purposes. The Cambridge Housing Model is closely linked to SAP 2012 and SAP 10, and it has been published for others to use.

Links to the 2011, 2012 and 2013 Housing Energy Fact Files, and Excel versions of the tables and plots included, are provided on the right. Other CAR work for DECC is available on our Household Energy Use page.