This document covers the requirements to help address overheating and limiting unwanted solar gain through glazing in buildings and to provide adequate means of quickly removing excess heat from indoor environments. It is appliable to a new dwelling, institution or any other building containing one or more rooms for residential purposes, but excludes a room within a hotel.
The requirements in this edition of Approved Document O are as follows:
O1 – Overheating mitigation
(1) Reasonable provision must be made in respect of a dwelling, institution or any other building containing one or more rooms for residential purposes, other than a room in a hotel (“residences”) to—
(a) limit unwanted solar gains in summer;
(b) provide an adequate means to remove heat from the indoor environment.
(2) In meeting the obligations in paragraph (1)—
(a) account must be taken of the safety of any occupant, and their reasonable enjoyment of the residence; and
(b) mechanical cooling may only be used where insufficient heat is capable of being removed from the indoor environment without it.
Limits on application
None
Regulation 40B: Information about overheating
(1) This regulation applies to building work in respect of a building where Part O of Schedule 1 applies.
(2) The person carrying out the work must, not later than five days after the work has been completed, give sufficient information to the owner about the provision made in accordance with Part O so that the systems in place further to Part O can be operated in such a manner as to protect against overheating.