Draft Residential Extensions & Householder Development Supplementary Planning Document

Ended on the 29 January 2018
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Garages and Outbuildings

4.1 Garages and other outbuildings can have a similar impact to other extensions on the existing dwelling. Any outbuilding should be subservient to the main dwelling and respect the materials, scale and character of the existing residential building(s).

4.2 In general, outbuildings should be situated in an inconspicuous position when viewed from the public realm. It will rarely be considered acceptable to site outbuildings in front of the existing property, as it would not appear subservient to the main dwelling and could conflict with any established building lines. Particular attention should be given to proposed outbuildings within a conservation area, and the setting of a Listed Building or neighbouring Listed Buildings.

4.3 Garages should be set back from the main building line and there should remain sufficient space forward of the garage for car parking. It is also desirable to provide turning space within the curtilage of the dwelling.



The illustration on the left shows an unacceptable design for a garage, which is set forward of the front main wall and is over-sized relative to the host dwelling. The drawing on the right shows an acceptable design, where the garage is set back from the dwelling, and is clearly subservient.

4.4 Outbuildings, as with other extensions, should not impact upon the amenity of any neighbouring property. They should not lead to an unacceptable increase in overshadowing, loss of privacy or disturbance. Where applicable, the 45o rule should be respected (see advice on rear extensions for details).


4.5 Annexes to existing dwellings are specifically intended to provide ancillary accommodation, for example to accommodate relatives or dependants. Such an annex should be designed to reflect the close functional relationship between the new accommodation and the existing dwelling: typically, it should not have a separate entrance or staircase, nor should it include a separate kitchen. This can be facilitated by ensuring that the annex is physically attached to the dwelling at all levels (e.g. for a two-storey annex, there should be internal connections on both storeys). Such an extension should not result in an overbearing structure, and should not overshadow adjoining properties (see above for specific guidance).

4.6 Where design constraints make it necessary to build a detached annex rather than an extension, the detached building can still remain functionally related to the existing dwelling through its design. A detached annex should share vehicular access and private amenity space with the host dwelling and should appear subservient to the dwelling in terms of its height, scale and mass. It should be located very close to the existing dwelling to support the shared use of communal (e.g. cooking and washing) facilities.

4.7 The use of an annex as ancillary accommodation will be controlled by a planning condition or a legal agreement.

4.8 Key Points For Garages, Outbuildings & Annexes:

  • Garages and outbuildings should respect the scale and character of the existing dwelling.
  • The siting of any outbuildings should respect any established building line or be set back from the existing dwelling.
  • Sufficient space for car parking and turning should remain between any proposed garage and the highway.
  • Proposals should not impact upon the amenity of any neighbouring property.
  • Annexes should be designed to reflect their status as ancillary accommodation for an existing dwelling, and should be physically attached or located very close to the dwellinghouse.

Boundary Treatments

4.9 Boundary treatments such as fences, walls and hedges, whether traditional or modern, contribute a great deal to the streetscape and character of an area. They are important for establishing the areas of private amenity space and often make a positive contribution to the settings of buildings. As such, careful thought should be given to the potential impact of their demolition. In conservation areas, consent to demolish will be required and is unlikely to be acceptable where harm would be caused to the streetscene. The substantial alteration of historic boundary treatments is unlikely to be acceptable.


The type of boundary treatment can have a significant impact on the streetscene. A more open, safe and visually interesting public realm can be created by designing new boundary treatments that create views into and out of residential properties.

4.10 Where new boundary treatments are proposed, care must be taken to ensure that the proposed materials and detailing are sympathetic to  the surroundings. Care should be taken to ensure that any proposed walls and fences do not harm the streetscene. Where residential areas have a distinctive, open or sylvan character, the erection of walls and fences over 1 metre at the front of the property is unlikely to be acceptable. The character of such estates is derived from the open, landscaped environment and physical, built barriers will significantly detract from that character. Likewise, boundary treatments that would obstruct visibility for highway purposes, or would otherwise cause danger to highway users will be unacceptable.


The introduction of walls and fences within a rural area will change the natural and open character of an area and create a more urban appearance.

4.11 Poorly designed boundary treatments can undermine the quality of the built environment and can negatively affect the relationships between buildings. New boundary treatments should generally be of the style typical of the immediate locality, unless an alternative would help to create a more active street frontage that would improve natural surveillance. New boundaries should be set back from the public highway and in all cases, the use of incongruous materials (e.g. a wooden fence when the area is characterised by brick walls) will be resisted.

4.12 In most cases, walls and fences that are less than one metre in height will not require planning permission, and this increases to a maximum of two metres on boundaries which are not adjacent to a highway.

4.13 Key Points for Boundary Treatments:

  • The removal or substantial alteration of traditional or historic boundary treatments is unlikely to be acceptable.
  • Boundary treatments should be designed in materials and details that respect the surrounding streetscape or area.
  • Boundary treatments should not be located directly adjacent to the highway.
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