Overheating in homes, and the duty arriving in October

For years overheating was treated as a comfort question, the sort of thing a fan and an open window dealt with. That framing has quietly fallen away. In 2023-24, 2.9 million households in England reported that their home got uncomfortably hot, and the same survey found newer homes more likely to overheat than older ones, despite being better insulated (English Housing Survey 2023 to 2024, climate resilient homes fact sheet). The summer of 2025 went on to be the hottest on record in the UK. A problem that affects millions of homes and gets worse each warm year is no longer a comfort issue. It is a safety one.

The rules are catching up

There are two strands of regulation, and they are moving towards each other. The first is Approved Document O, the overheating part of the Building Regulations, in force in England since June 2022. It applies to new residential buildings and asks the designer to show that a home will not overheat, either through a simplified method that limits glazing and provides ventilation, or through dynamic thermal modelling. It splits England into moderate and high risk areas, with London and the south-east at highest risk because of the urban heat island. Part O only governs new build, so it does nothing for the existing stock, which is where most of the 2.9 million sit.

The second strand reaches that existing stock. Excess heat is already a hazard under the Housing Health and Safety Rating System, the framework councils use to judge whether a home is fit to live in. From October 2026, the second phase of Awaab's Law brings excess heat, along with excess cold, fire, electrical safety, falls and more, inside the same statutory timescales that have applied to damp and mould since 27 October 2025 (Ministry of Housing, Communities and Local Government). For social landlords that means a reported heat hazard will carry a clock, not a best-endeavours promise. The Renters' Rights Act is expected to extend the same thinking to private rented homes.

What overheating actually asks of a manager

The practical work is not exotic. It is knowing which buildings are exposed, recording what you find, and acting on it before the weather does. Top-floor and south-facing flats, single-aspect homes that cannot cross-ventilate, and recently refurbished blocks with sealed, well-insulated envelopes are the ones to look at first. The risk is highest in dense urban settings where the surrounding city holds the heat overnight and the building never gets to cool down.

That assessment belongs in the same place as every other building risk, not in a separate spreadsheet that surfaces once a year. A risk assessment that flags the heat-exposed units, held against the building it relates to, is what turns a vague worry into a managed item. The seasonal side, a pre-summer check of communal ventilation, shading and any mechanical cooling, sits on a compliance calendar as a dated and owned task that chains to the next year rather than relying on someone remembering in May.

Why it becomes a records problem in October

The shift that October 2026 brings is not really about heat. It is about evidence. Once a hazard carries a statutory deadline, the question a regulator or a resident asks is no longer "is it hot" but "when did you know, and what did you do next". Answering that needs a dated trail: when the report came in, when you inspected, what you decided, and when the work was done. We made the same point when Awaab's Law arrived for damp and mould, and excess heat will work the same way.

None of this asks for anything heroic before the autumn. It asks managers to know which of their homes are exposed to heat, to write that knowledge down where the next person can find it, and to treat summer as the predictable risk it has become rather than the surprise it still gets treated as every June. The buildings that handle the next heatwave well will be the ones that did the boring part first.