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Changes to New Parts F, L and O in Wales

The new regulations amend the Building Regulations 2010 and the Building (Approved Inspectors etc) Regulations 2010 as they apply to Wales. They come into effect from 23 November 2022.

The changes can be found here

They introduce new energy efficiency ratings, new regulations for on-site electricity generation, amend Parts F and L and introduce a new Part O to mitigate overheating. Although the changes are similar to those in England there are differences such as in the definitions of the buildings to which the new Parts apply.

At the moment the new Parts F and L only apply to dwellings so the current Part F (2010 edition) and Parts L2A and L2B (2014 editions plus 2016 amendments) should continue to be used for the foreseeable future for buildings other than dwellings.

Copies of all the Welsh Approved Documents can be found here:

Welsh Approved Document Part 

Welsh Approved Document Part F

Welsh Approved Document Part O


Plan checking templates that include the 23 November 2022 amendments to Parts F Volume 1 – Dwellings; L Volume 1 – Dwellings; and O in Wales can be found in the links below together with the templates for the current versions of the building regulations and Approved Documents in Wales.


Welsh government webinar on parts F, L & O

Welsh Government is running an online webinar on the 17th of November 2022. 

Book your free place now



On 29 September 2022 the Welsh government issued a circular letter regarding the energy efficiency and ventilation amendments to the building regulations and Welsh Approved Documents L2 and F2.


This page was last updated on 19 October 2022