Which UK homes overheat most? What the housing record shows

Ask which UK homes overheat and most people say "flats in London". That is roughly right, but the reasons, and the exceptions, matter if you are choosing a home or deciding whether to fit cooling. So we measured it.

How we worked it out

The GetComfort Overheating Index runs the same scoring model the Home Cooling Checker uses across the real distribution of EPC ratings for four common home types in each of 133 areas, weighted by how common each type is there. Heat-island exposure is real, from Census density and settlement data. What we cannot yet read per home, such as which way it faces, is held at the same neutral value everywhere, so it does not distort the comparison between areas.

Home type: top-floor flats lead

• Top-floor flats sit directly under the roof, with nothing above to buffer the heat, and many face one way only.
• Victorian terraces have solid walls that store heat, and small rear rooms that can be hard to ventilate.
• Loft conversions put bedrooms under a thin roof with large windows, and vary widely with how well they were insulated.
• New builds score lowest on average, but modern airtightness can still trap heat where ventilation is poor, which is why Part O now tests new homes for overheating.

The places that run hottest

London dominates the top of the table, driven by its high share of flats, its old housing stock and a strong urban heat island. At the other end, Winchester, Lichfield, Dover, Ashford, Telford score lowest, with more houses, newer stock and less dense surroundings. The median area scores 38.

What the averages hide

An average is not your home. Two things push an individual home well above its area’s score: main rooms facing south or west, and being single-aspect so air cannot flow through. A heat-vulnerable occupant raises the stakes further. The checker asks about all three.

The climate is moving the whole table

The index scores homes against today’s climate. The Met Office’s local projections show the number of days above 30°C rising in every area as the world warms, fastest in London and the south-east. A home that is borderline now will be over the line more often, which is why a moderate score today is worth acting on with the cheap passive measures first.

How to use the index

• Buying or renting: compare the home type and area, then look at the specific flat or house, especially its floor and which way it faces.
• Landlords: top-floor and loft rooms in high-scoring areas are where tenant complaints and heat-health risks concentrate.
• Homeowners: use your area and home type as a starting point, then check your own address for a score based on its real records.