Side extensions in Epsom and Ewell depend on the house. Typical homes here: 1930s semi-detached houses in Stoneleigh, West Ewell, Ewell and the Epsom and Ewell part of Worcester Park; Edwardian and inter-war detached houses in Woodcote and around Epsom Downs. Designations to check first: Green Belt; Conservation areas; Hogsmill River flood risk. Applications are decided by Epsom and Ewell Borough Council and the Epsom and Ewell Core Strategy 2007 (new Local Plan emerging).
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 Epsom and Ewell
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 Epsom and Ewell are listed below, taken from our Epsom and Ewell area page. Each one is a reason to confirm the address on Epsom and Ewell's constraints map before relying on permitted development.
- Green Belt. A large share of the borough is Green Belt, including Epsom Common, Epsom Downs, the Hogsmill open space and land around Horton and Langley Vale. Source
- Conservation areas. Epsom town centre, Ewell Village, Stamford Green and Woodcote are among the borough's conservation areas. Source
- Hogsmill River flood risk. The Hogsmill River rises at Ewell and runs through Ewell Village, West Ewell and on towards Kingston, and land alongside it and its tributaries sits in Flood Zones 2 and 3. Source
- Article 4 directions. The council has used, or has consulted on using, Article 4 directions to remove particular permitted development rights, including for converting houses into small houses in multiple occupation and for works in some conservation areas. Source
- Listed buildings. Ewell Village, Epsom town centre and the old hospital estate at Horton contain listed houses, cottages, churches and institutional buildings. Source
What Epsom and Ewell planning officers look for
Epsom and Ewell Borough Council officers assess householder applications against the Core Strategy, the saved Development Management Policies and the council's supplementary guidance on residential extensions, with the emerging Local Plan carrying growing weight. On the 1930s semis that dominate Stoneleigh, West Ewell and Ewell 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. In the Green Belt officers usually measure the extension against the original dwelling by floorspace or volume and treat outbuildings more strictly. Common refusal reasons are full-width box dormers, side extensions that create a terracing effect, and roof extensions on front slopes in conservation areas.
Fees and timelines
Epsom and Ewell 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
- 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.
- Epsom and Ewell Borough Council: planning: the council's own constraints map, validation checklist and pre-application service.
