The Town and Country Planning (General Permitted Development) (Amendment) (Wales) Order 2013

Development not permitted

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 forms the principal elevation of the dwellinghouse;

(c) any part of the dwellinghouse would, as a result of the works, extend beyond the plane of any existing roof slope which—

(i) is comprised in a side elevation of the existing dwellinghouse; and

(ii) is within 10.5 metres from a highway opposite the side elevation of the dwellinghouse;

(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) other than in the case of a hip to gable enlargement, any part of the enlargement would be less than 20 centimetres from the eaves of the existing roof;

(f) it would consist of or include—

(i) the construction or provision of a veranda or raised platform ;

(ii) the construction or provision of a balcony which—

(aa) contains a platform of any description;

(bb) projects from the part of the exterior of the dwellinghouse to which it is affixed by more than 30 centimetres; or

(cc) if projected downwards in a vertical line to ground level, is within 10.5 metres of any boundary of the curtilage of the dwellinghouse opposite the relevant side elevation; or

(iii) the construction or provision of a roof terrace, whether or not it would incorporate associated railings, fencing or other means of enclosure; or

(g) the dwellinghouse is on article 1(5) land or within a World Heritage Site.