Part O – What You Need To Know 

Part O of the 2021 Building Regulations has been introduced to tackle overheating in residential buildings.Its aim is to mitigate overheating through unwanted solar gains and promote design that provides adequate means of removing excess heat from the indoor environment. It does not guarantee the comfort of residents but protects the health and welfare of occupants of the building by reducing the occurrence of high indoor temperatures.

Does Part O apply to your building?

Part O applies to all new residential buildings in England & Wales including dwellings, institutional buildings (i.e. schools or other similar establishments) where people sleep on the premises, and multi-use residential buildings (such as student accommodation).  Please note that shared communal rooms and common spaces of buildings containing more than one residential until fall within the scope of Part O, as well as live/work units that contain both living and space for commercial purposes.

Part O Overheating Calculations