13 Mar 2022
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United Kingdom
Hello all..

I'm researching a loft conversion under permitted development for a semi.

By my calculations a hip to gable and a dormer exceed the 50 cubic m volume allowed.

What I'm trying to find out is whether a hip to half hip (clipped gable, jerkinhead) roof is still allowed under permitted development?

Looked around and can't find a clear answer, any thoughts would be appreciated.

Thanks in advance.
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A hip would be allowed on a half gable, on the basis that it is not prohibited by the P.D.rules.

But are you sure you breach the 50m³ limit? This limit refers to the additional roof volume and does not include the volume of the existing roof void.
Thanks, appreciate the info. Can't see anything prohibiting the half hip.

I used the planning portal calculator to work out the volume. House is 7m by 7m. Ridge is 2m with a roof height of about 3m.

A full 7m dormer gives about 26m3. The gable is also a similar amount. So adding a small hip to the new gable should make it compliant.
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