# The Town and Country Planning (General Permitted Development) (Amendment) (Wales) Order 2013, Paragraph B.1: Development not permitted


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.

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Source: https://www.legislation.gov.uk/wsi/2013/1776/schedule/paragraph/B.1 (the official version)
Page: https://openlegislation.uk/town-and-country-planning-general-permitted-development-amendment-wales-order-2013/schedule/paragraph-B.1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.