Approved Document O

About Approved Document O

Approved Document O gives guidance on limiting overheating in new residential buildings. It covers how solar gain is limited, how excess heat is removed, and how the chosen strategy stays safe and usable.

What it covers

• Limiting unwanted solar gains in summer
• Removing excess heat, including natural and mechanical means
• The simplified method of showing a design meets the requirement
• Dynamic thermal modelling as an alternative method
• Keeping the overheating strategy usable, including safety from falling and entrapment
• Providing information to occupiers