Side extensions in Reigate and Banstead are mostly a 1930s semi question. In Nork, Banstead, Earlswood and Merstham the side of the house is where the garage sits, and the common project is a side extension with a kitchen or utility, sometimes with a room above. In the Reigate and Redhill villas the side return is narrower and the neighbour is close. On Reigate Hill and in Kingswood and Chipstead the large detached houses have wide side gaps that the council expects to be kept. The notes below are the council's own guidance on set-backs, garages and those gaps.
The permitted development rules for side extensions
A single-storey side extension is permitted development on a house if it is no wider than half the width of the original house, no higher than 4 m, with eaves no higher than 3 m where it comes within 2 m of a boundary, and finished in materials similar in appearance to the house.
Anything wider than half the original house, any two-storey side extension, and any side extension on a flat needs planning permission. Garage conversions that keep the walls are usually permitted development; extending beyond them is assessed as a side extension.
What changes in Reigate and Banstead
Side extensions are not permitted development in a conservation area at all, so there a planning application is always required.
The local constraints that most often decide the route in Reigate and Banstead are listed below, taken from our Reigate and Banstead area page. Each one is a reason to confirm the address on Reigate and Banstead's constraints map before relying on permitted development.
- Green Belt. Most of the borough outside Reigate, Redhill, Banstead and Horley is Green Belt, including land around Kingswood, Chipstead, Merstham, Salfords and the North Downs. Source
- Surrey Hills National Landscape. The North Downs above Reigate, including Reigate Hill, Colley Hill and the scarp towards Merstham, fall within the Surrey Hills National Landscape (formerly the Surrey Hills Area of Outstanding Natural Beauty). Source
- Conservation areas. Reigate town centre, Banstead, Chipstead, Kingswood and Merstham are among the borough's conservation areas. Source
- River Mole and Redhill Brook flood risk. The River Mole and its tributaries run through Horley, Salfords and Sidlow, and the Redhill Brook drains Redhill and Earlswood towards the Mole. Source
- Listed buildings. Reigate town centre, Banstead, Chipstead, Merstham and the villages contain many listed houses, cottages and churches. Source
Set-backs, roofs and garages at the side of the house
The council's Householder Extensions and Alterations SPG (March 2004) says a single-storey extension should use the same roof design as the main house and, where possible, the same pitch. It asks for a set-back from the front wall in proportion to the width of the extension, at least between 100 mm and 1,000 mm, to break up the frontage. Single-storey front extensions are rarely acceptable.
For garages it asks that an attached garage follows the single-storey extension approach, that a garage accessed directly from a public highway sits 6 m back so a car can park in front of it with the door open, and that converting a garage to living accommodation includes alternative car parking. It also discourages surfacing most of the front garden for parking.
Side gaps on larger plots
For the Residential Areas of Special Character, the 2021 Local Character and Distinctiveness Design Guide asks that the general pattern of gaps between side elevations and to boundaries be respected, that no part of a development be forward of the front building line, and that enough gap is kept at the side boundary for tree and hedge planting to be retained or provided. It also says single storey rear elements should have a generous gap to the side boundaries, usually 5 to 10 metres depending on the character of the road. A side extension on a Kingswood-style plot is read against that.
What Reigate and Banstead planning officers look for
Reigate and Banstead Borough Council officers assess householder applications against the Core Strategy, the Development Management Plan and the council's supplementary guidance on residential extensions. On the 1930s semis in Nork, Banstead, Earlswood and Merstham they tend to look for two-storey side extensions set back from the front wall and below the main ridge, a gap kept to the side boundary so the pair does not read as a terrace, and rear extensions that pass the 45-degree test to the neighbour's nearest habitable window. On Reigate Hill and in Kingswood and Chipstead plot coverage, tree protection and the spacious, wooded character of the road carry more weight, and inside the Surrey Hills the landscape impact is tested too. Common refusal reasons are full-width box dormers, side extensions that create a terracing effect, and disproportionate additions in the Green Belt.
Fees and timelines
Reigate and Banstead decides a householder application or a Lawful Development Certificate within 8 weeks of validation. The council fee is £528 for a householder application and £264 for a Lawful Development Certificate (England, from 1 April 2025; verify before applying).
Our own fee is fixed once quoted. The quote tool gives an indicative figure in minutes and a written quote follows within 24 hours.
Primary sources
- Reigate and Banstead Borough Council: Householder Extensions and Alterations SPG (March 2004)
- Reigate and Banstead Borough Council: Local Character and Distinctiveness Design Guide SPD (June 2021)
- The Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2: the permitted development limits quoted above.
- Planning Portal: do you need permission: the national guidance and the application service every council accepts.
- Reigate and Banstead Borough Council: planning: the council's own constraints map, validation checklist and pre-application service.
