Development not permitted
B.1 Development is not permitted by Class B if—
(a)permission to use the dwellinghouse as a dwellinghouse has been granted only by virtue of Class M, N, P or Q of Part 3 of this Schedule (changes of use);
(b)any part of the dwellinghouse would, as a result of the works, exceed the height of the highest part of the existing roof;
(c)any part of the dwellinghouse would, as a result of the works, extend beyond the plane of any existing roof slope which forms the principal elevation of the dwellinghouse and fronts a highway;
(d)the cubic content of the resulting roof space would exceed the cubic content of the original roof space by more than—
(i)40 cubic metres in the case of a terrace house, or
(ii)50 cubic metres in any other case;
(e)it would consist of or include—
(i)the construction or provision of a verandah, balcony or raised platform, or
(ii)the installation, alteration or replacement of a chimney, flue or soil and vent pipe; or
(f)the dwellinghouse is on article 2(3) land.