Garden rooms and outbuildings in Richmond upon Thames depend on the house. Typical homes here: Georgian and Regency houses on Richmond Hill, in Petersham and around Richmond Green; Victorian terraces in Twickenham, St Margarets, Mortlake and East Sheen. Designations to check first: Conservation areas; Article 4 directions; Thames flood zones. Applications are decided by London Borough of Richmond upon Thames and the Richmond upon Thames Local Plan.
The permitted development rules for garden rooms and outbuildings
An outbuilding is permitted development on a house if it is single storey, no higher than 2.5 m where it comes within 2 m of a boundary, otherwise no higher than 4 m with a dual-pitched roof or 3 m with any other roof, sits behind the front wall of the house, covers together with other outbuildings no more than half the land around the original house, and is used for purposes incidental to the house rather than as a bedroom or self-contained flat.
Anything used for sleeping or as a separate dwelling needs planning permission regardless of size. Flats have no permitted development rights for outbuildings, and listed buildings need listed building consent.
What changes in Richmond upon Thames
In a conservation area an outbuilding is still permitted development behind the house, but not to the side of it, and the same height limits apply.
The local constraints that most often decide the route in Richmond upon Thames are listed below, taken from our Richmond upon Thames area page. Each one is a reason to confirm the address on Richmond upon Thames' constraints map before relying on permitted development.
- Conservation areas. Richmond has 85 conservation areas, covering a large share of the borough's housing. Source
- Article 4 directions. Many Richmond conservation areas carry Article 4 directions removing permitted development for front elevations, windows, porches, boundary walls and hardstandings. Source
- Thames flood zones. Low-lying land at Barnes, Mortlake, Kew, Twickenham riverside, Teddington and Hampton falls within Flood Zones 2 and 3. Source
- Metropolitan Open Land and Royal Parks. Richmond Park, Bushy Park, Kew Gardens (a World Heritage Site) and Ham Lands are Metropolitan Open Land or protected landscapes.
- Listed buildings. The borough has a high number of listed buildings, particularly around Richmond Green, Richmond Hill, Petersham, Twickenham riverside and Hampton.
What Richmond upon Thames planning officers look for
Rear extensions deeper than neighbouring precedent, roof extensions that are not clearly subordinate, and front dormers are common refusal reasons. In conservation areas expect detailed comments on windows, brick and rainwater goods. Pre-application advice is available for a fee and, in our experience, is worth it for anything in a conservation area or on the river.
Fees and timelines
Richmond upon Thames 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.
- London Borough of Richmond upon Thames: planning: the council's own constraints map, validation checklist and pre-application service.
