Overview

With a median EPC rating of C - 70, domestic properties in London are more energy efficient than the English average of D - 68. London is the most energy efficient region of England for domestic properties. This report contains UK and London specific domestic EPC data compiled from publicly available government data sources and analysed by our team.

Comparisons

By Tenure

Typically, the most efficient type of properties in London by tenure are socially rented properties.

By Property Type

Flats and maisonettes are typically the most efficient type of property by property type.

By Construction Date

As heating technology and building standards have evolved, the quality of housing being built has also increased. Older buildings typically have worse EPC ratings. London still has a large quantity of older housing stock and many of the dwellings which people live in were originally built before modern standards for insulating and heating were put into place.

City Comparison

London is also the second most efficient city out of the top 10 largest cities (by population) in England for domestic EPCs, the only more efficient being Manchester with a median domestic EPC rating of 71.

Fig 2. Bar chart of populous cities median domestic energy efficiencies.

Borough Efficiency

Which London boroughs are the most and least efficient?

The London borough with the most efficient housing is Tower Hamlets with a median domestic EPC rating of C 78, the highest of any local authority in England or Wales. The London boroughs with the least efficient housing are Bexley, Bromley, Enfield, and Havering all with a joint median domestic EPC rating of D 66.

List of London boroughs domestic median efficiency:

Median domestic EPC ratings in London

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Fuel Sources

The main fuel source used for heating homes in England is mains gas with 80% of the 27,966,809 domestic EPCs we analysed using it as a main fuel source, mains electricity was a main fuel source for an additional 13% of domestic properties. The remaining properties used other types of fuel such as community heating schemes, LPG or biofuels like wood.

Properties with mains gas as a main fuel source tend to have worse EPC ratings on average than properties with mains electricity as a fuel source. This is because systems which use mains gas are calculated to be less efficient in the RdSAP calculations than systems which use mains electricity and using mains gas also decreases EPC ratings further as it typically causes a larger amount of CO2 to be released than other fuel sources.

We analysed 4,260,017 Domestic EPC Records in the London area and found that 79% had mains gas as a main fuel source and 13% used mains electricity as a main fuel source.

The London borough which had the fewest domestic properties which used mains gas as a main fuel source was the City of London, with only 34% of properties having mains gas as a main fuel source. The London borough with the highest percent of domestic properties which used mains gas as a main fuel source was Bromley with 88% of properties having mains gas as a main fuel source.

Future Legislation

As of July 2025, the current Minimum Energy Efficiency Standards (MEES) require domestic private rented properties in England to have an EPC rating of at least E since April 2020, with a cost cap of £3,500 for improvements and penalties up to £5,000 for non-compliance. Exemptions include high cost, third-party consent, and property devaluation, valid for 5 years.

The UK government is consulting on proposed legislation to raise standards, potentially implementing new EPC metrics (fabric performance, heating system, smart readiness) from 2026, requiring new tenancies to meet higher standards by 2028 and all tenancies by 2030, with a proposed cost cap of £15,000 and penalties up to £30,000. We analysed 1,321,223 domestic EPCs for privately rented London dwellings and found that 55.2% are currently below a C rating – if the proposed legislation goes through, all of these properties will require upgrades to HVAC, lighting, or their construction to improve their EPC rating.

Improvements

Potential Improvements

There are several areas London should focus on to improve the efficiency of its dwellings. The average amount London dwellings can improve by is between 10-11 points. The Borough with the greatest potential for improvement is Havering with an average potential improvement of about 15 points per Domestic EPC. The borough with the lowest potential for improvement is Tower Hamlets with an average of about 5 points of improvement per Domestic EPC.

Heat Pumps

One of the main things that should be focused on to improve builds is the transition from natural gas as a heating source to a greater usage of mains electricity. Better insulation and more energy efficient lighting such as LEDs will also reduce energy usage and CO₂ emissions (these recommendations are general advice and may not be the right thing to do to improve efficiency in all properties. Proper consultation should be booked before committing to any improvements. ). One of the things we have found improves EPC ratings of buildings the most is radiators being swapped out for air source heat pumps which (in general) heat buildings far more efficiently using mains electricity.

Very few domestic buildings in London use heat pumps, the borough which has the most domestic properties with heat pumps is The City of London with still just 2% of buildings using heat pumps as a main source of heating.