Summertime overheating in dwellings in temperate climates

Summertime overheating in both new and existing dwellings is widespread and increasing, even in temperate climates. There is an urgent need to solve the problem. Flats (apartments) and small dwellings, especially those in cities, are particularly at risk. Elderly and vulnerable people are particularly affected. This briefing note presents current knowledge about this problem and what might be done about it. It is directed at planners, designers, policymakers as well as local authorities, housing associations and other organisations that manage stocks of dwellings.

Key findings

The research community and others have revealed the extent, severity and causes of summertime overheating in dwellings.

Flats, even in temperate climates, are particularly at risk of overheating. Methods of construction and refurbishment and global warming are making the problem worse.

Overheating affects mortality and morbidity, with the elderly and vulnerable particularly affected.

Well-established passive heat-protection measures can, in most cases, prevent or remove the problem.

Examples of good design practice are being verified through monitoring and occupant experience surveys.

Professionals concerned with the design and refurbishment of dwellings must now focus on keeping them cool in summer as well as warm in winter.