ABSTRACT
B.1-Development is not permitted by Class B if-(a) any part of the dwellinghouse would, as a result of the works, exceed the
height of the highest part of the existing roof; (b) any part of the dwellinghouse would, as a result of the works, extend
beyond the plane of any existing roof slope which fronts any highway; (c) it would increase the cubic content of the dwellinghouse by more than 40
cubic metres, in the case of a terrace house, or 50 cubic metres in any other case;
(d) the cubic content of the resulting building would exceed the cubic content of the original dwellinghouse-(i) in the case of a terrace house by more than 50 cubic metres or 10%,
whichever is the greater, (ii) in any other case, by more than 70 cubic metres or 15%, whichever is
the greater, or (iii)in any case, by more than 115 cubic metres; or
(e) the dwellinghouse is on article 1(5) land.
