Permitted Development - Class B

[Bricks & Mortar]

Hi all, hoping someone may be able to provide some insight into what roof enlargements you can make under Permitted Development Class B.

I am particularly interested in condition B.2(b)(ii) which states:

"other than in the case of an enlargement which joins the original roof to the roof of a rear or side extension, no part of the enlargement extends beyond the outside face of any external wall of the original dwellinghouse"

Does this prevent any additions being made (e.g. a dormer) above a previous extension, therefore roof enlargements can only be made above the original dwelling?

The technical guidance document provides the following information:

"The enlarged part of the roof must not extend beyond the outer face of any wall of the original house if it is to qualify as permitted development, unless it joins the original roof to the roof of a rear or side extension. An interpretative provision at paragraph B.4 of Class B clarifies that for these purposes any roof tiles, guttering, fascias, barge boards or other minor roof details which overhang the outer face of the wall should not to be considered part of the roof enlargement.

The enlarged part of the roof may join the original roof to the roof of a rear or side extension (generally referred to as an ‘L-shaped dormer’ on a main roof and ‘outrigger’ or ‘back addition’ roof), whether the part of the house being extended forms part of the original house or is an enlargement, or the shape or level of the pitch of the roofs are different in relation to each other."

I'm struggling to fully appreciate what is allowed based on above, i.e. could a hip to gable be undertaken above an existing side extension if it joins onto the original roof?

Any thoughts or examples would be appreciated.

Thank you.

 

[wessex101]

Generally there is no permitted development allowed to extend or enlarge a previous new extension or enlargement. (Unless there is some unused PD allowance such as enlarging an extension from 2m deep to 3m and still be within PD limits).

I cannot see how you would get a hip to gable conversion on a previous side extension roof under PD but I might be wrong.

 

[robinbanks]

Can you make a 3D sketch of the before and after of what you want to do?

 

[Bricks & Mortar]

Generally there is no permitted development allowed to extend or enlarge a previous new extension or enlargement. (Unless there is some unused PD allowance such as enlarging an extension from 2m deep to 3m and still be within PD limits).

I cannot see how you would get a hip to gable conversion on a previous side extension roof under PD but I might be wrong.

I had thought that this might be the case based on condition B.2(b)(ii), though was interested how others interpreted this condition.

Can you make a 3D sketch of the before and after of what you want to do?

This is a rough sketch of the arrangement.
The blue section is a previous extension and the red section is the potential hip to gable conversion we're considering.

Thanks

 

[robinbanks]

If that sketch is dimensionally accurate (or close enough) can you tell us what the original volume of the roof space is, how much volume the blue part added and how much volume the red part then adds?

 

[^woody^]

but I might be wrong.

You may be right. Stay positive.