Overheating Assessments

An Overheating, assessment checks to see if a building is likely to be too hot. Approved Document O is the government’s formal advice for preventing this in residential accommodation. It requires all newly built residential accommodation to provide evidence that overheating has been considered and mitigated.

To pass the overheating test, a building needs to:

• Limit sunlight coming in: This means using things like blinds, shades, or specific types of glass.
• Let heat escape: Buildings need enough openable windows or vents to release warm air.
• Consider the building’s location: Where a building is placed and orientated affects how much sun it gets.

By following the guidance, Approved Document O helps make certain homes stay cool and comfortable, even on hot days.