Planning permission for loft conversions is not normally required unless you extend or alter the roof space and it exceeds specified limits and conditions.
A loft conversion for your house is considered to be permitted development, not requiring an application for planning permission, subject to the following limits and conditions:
- A volume allowance of 40 cubic metres additional roof space for terraced houses or 50 cubic metres additional roof space for detached and semi-detached houses (this must include any previous roof space additions).
- No extension beyond the plane of the existing roof slope of the principal elevation that fronts the highway.
- No extension to be higher than the highest part of the roof.
- Materials to be similar in appearance to the existing house.
- No verandas, balconies or raised platforms.
- Side-facing windows to be obscure-glazed; any opening to be 1.7m above the floor.
- Roof extensions, apart from hip to gable ones, to be set back, as far as practicable, at least 20cm from the original eaves.
- The roof enlargement cannot overhang the outer face of the wall of the original house.
There are also restrictions placed on any property within a National Park, an Area of Outstanding Natural Beauty or a Conservation Area.
If your project does require planning permission, it will take eight – ten weeks for the council to reach a final decision.
For more information, visit the Planning Portal website for a visual guide.