Energy efficiency of UK homes

The average energy efficiency of UK homes has steadily improved over time, but the rate of improvement has slowed since 2014. The latest comparable data shows that homes in Northern Ireland had the highest average energy efficiency rating, followed by Scotland and England, with the lowest average rating in Wales.

This briefing looks at data on energy efficiency levels across the nations of the UK, variations by different types of properties and households, insulation measures and government funded/mandated energy efficiency schemes.

Progress on energy efficiency in the UK

There has been faster progress on the percentage of homes with an energy efficiency rating of band C or higher. In England the share at this level increased from 12% in 2010 to 52% in 2022. The latest data shows a higher rate on this measure in Scotland and lower rates in Northern Irelands and Wales.

The Government has a target that all fuel-poor homes should be at least band C by 2030 and an aspiration for as many as possible homes across the country to be at least band C by 2035.

Factors affecting energy efficiency

The factors linked most strongly to energy efficiency are a property’s age and type. Newer homes have much higher ratings, as do purpose-built flats, while older homes, converted flats and bungalows have the lowest average ratings.

Levels of insulation

An estimated 5.1 million properties in Great Britain with cavity walls have no cavity wall insulation; 24% of the total. Around 7.9 million homes with lofts (31%) have less than 125mm of loft insulation and 7.7 million homes with solid walls (90% of the total) do not have solid wall insulation.

Energy efficiency schemes

There are a wide range of different schemes across the UK to help improve the energy efficiency of homes. Most of these are targeted at lower income households living in less energy efficient properties. Some schemes are taxpayer funded, others are delivered by energy suppliers and funded through a levy on energy bills.

The Energy Efficiency Obligation (ECO) has been the main energy efficiency scheme over the last decade delivering 4.1 million measures in 2.5 million homes between 2013 and autumn 2024. It is funded by a levy on household energy bills, but the government sets the overall scheme targets and rules. The number of number of measures under ECO fell during the second half of the 2010s from more than 80,000 per month in early 2014 to less than 20,000 per month (on average) from mid-2016 to mid-2020.

Source: DESNZ, Household Energy Efficiency Statistics, headline release January 2025

There was a “significant drop” in April 2014 when the Government reduced part of the target for suppliers in order to help reduce energy bills.

Longer term data on shows a sharp drop in both loft and cavity wall installations carried out under government schemes in 2013 when ECO and the short-lived Green Deal replaced existing energy efficiency schemes. There was a small increase in 2014 (before the changes to ECO), but further falls afterwards and no sign of a clear increase in any of these types of insulation up to the end of 2023.

 Source: DESNZ, Household Energy Efficiency Statistics, detailed report 2023, and earlier editions (Table 8.3)