The key criteria are:
- Maximum 3m depth, for an attached property, or 4m for a detached*. These dimensions can be doubled (referred to as ‘larger extensions’ In the legislation) but are subject to neighbour agreement.**
- Maximum eaves height of 3m and no-higher than the existing eaves with a maximum total height of 4m overall.
- The total area of non-original extensions must not exceed 50% of the area around the original house And no closer than 7m from the rear boundary.
- Materials should be ‘of similar appearance to the original house.
* Although planning permission is not required, we recommend submitting an application for a Certificate of Lawfulness to get formal confirmation that the design complies with the rules.
** An application for ‘Prior Approval’ must be submitted for a ‘Larger extension’.
Two story rear extensions will generally require planning permission – please contact us regarding full bespoke design services.