Calculating loft volume and applying for LDC

[KateK]

You are just calculating the volume of the new dormer, not the entire roof space including the existing roof? 57m³ is bloody huge.

L-shaped semi with a hip to gable, so building over the outrigger adds a few cubic metres.

 

[wessex101]

Oh, that explains the 57m³. All you can do then is try the LDC with the internal dimensions and see what happens, quote Woody as your expert witness. Might be worth studying appeals to see if you can find any examples that agree with the internal volume argument.

Good luck, and don't forget to come back and tell us the outcome.

 

[napoleondynamite]

In my experience- volume will be calculated based on external measurements, and the Council will measure from your drawings. The volume check is one of the basic checks they will tick off, long with the 200mm set back from the eaves, side facing windows being obscured and fixed shut up to 1.7m, materials proposed matching the main house (e.g. clad in tiles to match the main roof, windows to match those of the main house etc.) etc.

If your drawings measure over 50m3 externally you are likely to get a refused LDC.

However we all know LDC are not requirements, and they are paper exercises and the drawings are often not complied with on site, so really is down to you to decide whether you want to build something which needs planning permission or not. And if you do need permission, whether you apply for permission or wing it is your call.

LDCs are a red herring- it's about whether it needs permission or not.

Planning Jungle summarises all appeal decisions and I imagine this issue is covered by PJ, but you need someone with a subscription to PJ to take the time to go through it.