Planning Permission & floor space

[LouUK]

Hi I wondered if anyone knew the regulations?
I am in a semi-detached house and my adjoining neighbours keep extending their house in every way possible (forwards-back-sideways-up).
What is the maximum of extending/conversion that you can do?
Can extensive extension work affect any adjoining properties structually or value?
Please help!

[jake-the-peg]

Permitted Development Rights enable you to extend up to 15% of the existing house in volume, or 70cu m, whichever is the greater. For terraced houses, this is reduced to 10% or 50m3. In both cases, the maximum enlargement is 115cu m. The volume is reduced to 10 per cent or 50cu m within Conservation Areas. In Scotland, the figures seem to be 20 per cent or 24sq m. The extensions must be no higher than the existing house and if within 2m of a boundary, a pitched roof structure mustn�t be higher than 4m or a flat roof 3m.

more than that requires planning permission

[buildersmate]

Above is correct for modifying without Planning Permission. But they may well be applying for Planning Permission each time. In that case, no limit if they get the permission.

[LouUK]

Thank you very much for both of your responses. They have definately done more than 15%, cu m I can't say as that is too technical for me!

What about this part "Can extensive extension work affect any adjoining properties structually or value? "

Thank you for your help so far though :-)