08 June 2018
Two-storey extensions don’t normally require planning permission. But regulations must be closely considered. We have written this post to provide a walk through of the limitations and conditions of a two-storey extension. It is important to note that the permitted development in this post only applies to houses, not flats or other buildings. Make sure to always check with your local authority if permitted development rights apply.
- House with designated land. On designated land, extensions more than one storey high and are not permitted development.
- Area permitted. Extensions must not be larger than 50% of the total area around the original house. The term ‘original house’ means the house that existed before 1 July 1948, if it was built before this date. You may not have built an extension to the house, but a previous owner might have done. When calculating the over 50% limit, outbuildings such as sheds must also be included.
- Eaves and roof height. The eaves and ridges should be no higher than the height of the existing house. If the new extension falls within the two-meter boundary, the eaves should be no higher than three meters. This ensures that the development can be permitted.
- Depth. Two storey extensions should not go beyond the rear wall of the house by three meters. And it should not be within seven meters of any boundary opposite the rear wall of the house.
- Roof pitch. The pitch of the roof of extension should be the same as the existing house as much as is possible.
- Materials. Materials that are used to construct the extension should be similar to those that have been used to construct the original house.
- Side windows. Upstairs windows in a new extension should contain obscured glass and should not be able to open. Unless the openable parts are above 1.7 meters above the floor of the room it has been installed in.
- Balconies. Balconies and verandas are not permitted development.
Planning permission is not usually required for two storey extensions, as long as a number of requirements are abided. In this post, we have outlined these considerations. However, we have only outlined these for house. Not flats or other outbuildings. If you are unsure about development requirements in your local area, always check with your local authority to make sure that the changes are allowed.
How can Phoenix Design Management help me with my new house extension?
Phoenix Design Management are proud to say that they have 17 years’ experience of planning and building small housing extensions. We work closely with our clients, allowing us to create designs that are truly bespoke to them. But we also understand that some clients require inspiration and ideas. And we would be happy to offer this. If you are thinking about building a house extension, contact us today and see how we can help. ❮ Back to Blog