Will this new dormer be a permitted development or do I need planning?

3 Jun 2016
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United Kingdom
Hi, I have a technical question for anyone with planning experience. We've already had drawings approved to extend our semi (not yet built), however if we now apply afresh for a loft coversion as shown in red on the attached, will it be a straight forward permitted development? The key issue is, because we've already had our roof extended, does that mean we have now lost this permitted development right (even though it meets all the parameters for a permitted development loft)? Many thanks in advance! Adam


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That would need planning permission because:
1. the dormer is directly connected to the side-extension roof (the 2 projects are regarded as one for the purposes of planning law);
2. the total roof enlargement would probably exceed 50m³.
Many thanks Tony! The side extension roof is approx 43m3 and because I need a decent loft yes it will be over 7m3. As shown on the side elevation, the dormer will poke out a bit (albeit lower than the ridge), and also on the roof plan the dormer will cut slightly into the other rear-extension roof, will both these be acceptable?

One more question, can I apply for the dormer permission as soon as the side extension's foundations are dug or only when the side extension is 'substantially complete'? This is because ideally we want to do both roof projects in one go and not a few months apart.

The reason for not applying for the side & dormer extensions together is (a) it has a greater chance of rejection due to overdevelopment and (b) also a £12k tax charge for extensions over 100sqm (community infrastructure levy). Thanks
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Hi, yes with the double storey side/rear it's totalling 72m2, plus the dormer's habitable space (excluding nooks & crannies) of approx 40m2?
Is something off with the scale? The dormer can't be more than 28m³ (externally) and the side extension 13m³ !?!
Is something off with the scale? The dormer can't be more than 28m³ (externally) and the side extension 13m³ !?!
I was referring to the floor area upon which the tax is payable (not volume). The roof space internally, once habitable will be approx 40sq m.

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