Approved Document O Wales

Approved Document O (2022 edition – Wales) was released in May 2022 and came into force for all Building Regulations building notices, full plans applications and initial notices for residential buildings submitted in Wales from 23 November 2022.

Residential buildings include dwellings (houses and flats), care homes, nursery school sleep rooms and residential colleges, halls of residences and other student accommodation for children aged 5 years and older.

Government regulation

Compliance

Like the English version, there are two routes to demonstrate compliance with Requirement O1(1):

1. The Simplified Method: a prescriptive approach, which defines maximum glazed areas and minimum window open areas, which can only be used where apartment district heating systems are not distributed in the common

2. Dynamic Thermal Modelling: a computational method offering additional design flexibility over the Simplified Method.

However, unlike the English version, whilst the legal requirement remains the same, there are differences in the guidance, including more flexibility in the Simplified Method, no need for a strategy for cross-ventilation dwellings and student accommodation provided there are no constraints to ventilation openings due to noise, pollution, safety or security and noise at night only needing to be taken into account where the local planning authority considered it to be an issue.

Overheating in buildings has been highlighted as a key risk for the health and productivity of people and businesses in the UK

It is estimated that there are about 2,000 heat-related deaths each year in England and Wales.

This has led to new regulations to ensure occupants in new residential buildings do not suffer excessive temperatures.

Approved Document O England

Approved Document O (2021 edition – England) was released in December 2021 and came into force for all Building Regulations building notices, full plans applications and initial notices for residential buildings submitted in England from 15 June 2022.

Approved Document O Wales

Approved Document O (2022 edition – Wales) was released in May 2022 and came into force for all Building Regulations building notices, full plans applications and initial notices for residential buildings submitted in Wales from 23 November 2022.

Scottish Building Standard 3.28

Standard 3.28 of the Scottish Building Standards Domestic Technical Handbook (December 2022 edition) was released in June 2022 and came into force for all residential Building Warrant applications submitted in Scotland from 01 February 2023.