Extensions

You need to apply for planning permission to extend or add to your house in the following circumstances.

• You want to build an addition which would be nearer to any highway than the nearest part of the "original house", unless there would be at least 20 metres between your house (as extended) and the highway. The term "highway" includes all public roads, footpaths, bridleways and byways. (There are special rules for porches.)
• More than half the area of land around the "original house" would be covered by additions or other buildings.

The term "original house" means the house as it was first built or as it stood on 1 July 1948 (if it was built before that date). Although you may not have built an extension to the house, a previous owner may have done so.

You will also need to apply for planning permission if the extension or addition exceeds certain limits on height or volume.