HS11 House Extensions Policy
Proposals for house extensions will be permitted subject to all the following criteria being complied with:
(i) the scale of the extension being appropriate to the size of the plot, not dominating the existing building and not so extensive as to be unneighbourly, particular regard being had to the effect on light to and the outlook from neighbours' habitable rooms and not so arranged as to result in significant overlooking of neighbouring residential property.
(ii) the materials matching or complementing those of the existing building;
(iii) design features such as lintels, sills, eaves and roof form and line matching or complementing those of the existing building;
(iv) dormer windows if used, being restricted to the rear of the dwelling and not projecting above the ridge, nor occupying the full width of the roof;
(v) flat roofs being restricted to the rear or side of the dwelling and only acceptable on single storey extensions;
(vi) where the rear extension is single storey on the party boundary and the existing dwelling semi-detached, the proposed extension projects a maximum of 3.0 metres from the main face of the existing houses;
(vii) where the rear extension is two storey and the existing house semi-detached, the proposed extension is set back at least 2.5 metres from the party boundary;
(viii) to avoid the effect of ‘terracing’, where two storey side extensions are added to the sides of semi-detached houses of similar style with a consistent building line and ground level, the first floor of a two storey side extension should be set back at least 1.5 metres from the common boundary; or at least 1.0 metre from the front elevation and 1.0 metre from the common boundary; or at least 2.0 metres from the front elevation;
(ix) single storey extensions on terraced dwellings allowing an adequate area of amenity space to be retained.
Reasoned justification :
6.57 House extensions should be designed in such a way as to have no significantly adverse effect on the appearance of the original property, the amenities of neighbouring properties, particularly through overlooking, or an adverse effect on the area in general.
6.58 Well-designed house extensions should be constructed of materials which match those of the original dwelling and echo its form, for example, with respect to its roof line. Single storey flat roof extensions are only appropriate where they are unobtrusive, at the side or rear of the dwelling.
6.59 In areas of semi-detached housing, the Local Planning Authority is concerned to avoid the terracing effect of two storey side extensions and wishes to see a larger set-back than would otherwise be necessary, where there is a greater separation between dwellings.
6.60 Whilst the restrictions on extensions to detached dwellings are often less onerous, in areas of terraced housing it is important to retain some private amenity space at the rear of the dwelling whilst providing often essential facilities such as kitchen and bathroom extensions. Further guidance with regard to house extensions is contained in Supplementary Planning Guidance Note 11.