F-4 Permitted Development for Homeowners
The extension above is a side Extension and a Hip to Gable loft conversion see (0825)
If you have a semi-detached house you can normally extend to the front, back and side as well as the loft with rear facing dormers.
IF you have a detached house you can also do this but go further backwards with rear extensions and size of rear dormers.
Front is limited 3m2 for a porch
Side and up to the boundary max 3m high if a flat roof
Rear is 3m if semi or 4m if detached; this is doubled to 6m and 8m, if neighbours allow you to pass the Enhanced Permitted Development test (Larger Householder Rear Extension application)
If any of the two Permitted development touch then you need planning permission to join them.
Oddly a side extension can also have a 3 or 4m rear projection and still be permitted development.
Assembling the Permitted Developments can take a lot of time and Planning Appeals can slow the whole assembly process – thus are often best avoided.