PPS 7 (Addendum): Residential Extensions and Alterations
Annex A: Context and Design: Garages and Other Associated Outbuildings
A11 Buildings within the residential curtilage, such as, garages, sheds and greenhouses can often require as much care in siting and design as works to the existing residential property. They should be subordinate in scale and similar in style to the existing property, taking account of materials, the local character and the level of visibility of the building from surrounding views. The use of false pitches should be avoided as these often detract from the appearance of these buildings, particularly when viewed from the side.
A12 Garages or outbuildings wholly located in front gardens or those that extend in front the established building line can over-dominate the front of the property and detract from the street scene and will therefore generally be resisted.
A13 In the countryside, ancillary buildings should be designed as part of the overall layout to result in an integrated rural group of buildings