Rooftop extensions to dwellings
Planning applications with suffix BFL56
Following the revised permitted development rights adopted in September 2020, rooftop extensions are allowed without obtaining planning permission but following a prior approval process. Here is a summary of the rules:
- The building must have been built between July 1948 and October 2018
- Single-storey buildings can be extended by one storey and others up to two storeys
- Height: The building must not exceed 18 metres in total height, and each added storey cannot add more than 3.5 metres to the total height. If the house is in a terrace or semi-detached, the total height cannot be more than 3.5 metres higher than the next highest building that the house is attached to, adjoins, or is in the same row as
- The additional storeys must be constructed on the principal part of the building
- Engineering operations must only include works within the existing curtilage of the building to strengthen existing walls and foundations
- The materials used must be of a similar appearance to those used in the construction of the exterior of the current building
- Windows must not be placed in any wall or roof slope forming a side elevation
- No visible support structures must remain on. or be attached to. the exterior of the building
- The roof pitch of the principal part of the building must be the same as it was prior to the development
There are further limitations to designated areas, such as conservation areas
- Permitted Development Rights to extend buildings upwards
- House of Commons briefing paper on new PDRs (PDF)
So far there has been just one application in Headington for such a rooftop extension, approved on 13 December 2021:
Flats 1–9 Girdlestone Close
Application by Lucy Developments for prior approval to create a two-storey roof extension to provide 6no. flats (Use Class C3):
- Prior approval required and granted: 21/02767/BFL56
