Rear extensions in Wandsworth depend on the house. Typical homes here: Victorian terraces "Between the Commons" around Northcote Road, Balham and Clapham Junction; Edwardian terraces and semis in the Southfields Grid, Earlsfield and Wimbledon Park. Designations to check first: Conservation areas; Article 4 directions; Thames and Wandle flood zones. Applications are decided by London Borough of Wandsworth and the Wandsworth Local Plan 2023.
The permitted development rules for rear extensions
On a house, a single-storey rear extension is permitted development if it projects no more than 3 m from the original rear wall on a terraced or semi-detached house, or 4 m on a detached house, is no higher than 4 m, has eaves no higher than 3 m where it comes within 2 m of a boundary, and uses materials similar in appearance to the house. The larger home extension route allows 6 m or 8 m through a 42-day prior approval, where the council consults the neighbours.
Flats and maisonettes have no householder permitted development rights, so any rear extension to a flat needs planning permission. Previous extensions count against the allowance, and the larger home extension route is not available in conservation areas.
What changes in Wandsworth
In a conservation area a single-storey rear extension can still be permitted development within the 3 m or 4 m limit, but cladding it in materials that differ from the house is not, and the 6 m and 8 m prior approval route is closed.
The local constraints that most often decide the route in Wandsworth are listed below, taken from our Wandsworth area page. Each one is a reason to confirm the address on Wandsworth's constraints map before relying on permitted development.
- Conservation areas. Wandsworth has numerous conservation areas, including large ones covering the streets between Wandsworth and Clapham Commons, Putney, Tooting Bec, Wandsworth Common and Nightingale Lane. Source
- Article 4 directions. A number of Wandsworth conservation areas carry Article 4 directions removing permitted development for front alterations, windows, porches and boundary treatments.
- Thames and Wandle flood zones. Battersea, Nine Elms, Wandsworth Town and Putney riverside fall within Thames Flood Zones 2 and 3, and the Wandle corridor through Earlsfield and Summerstown adds further flood risk. Source
- Metropolitan Open Land. Wandsworth Common, Clapham Common, Tooting Common, Putney Heath and Wimbledon Park are Metropolitan Open Land.
What Wandsworth planning officers look for
Rear extensions deeper than neighbouring precedent, side-return infills with parapets above the neighbour's fence line and roof extensions in conservation areas are the common refusal reasons. Pre-application advice is available for a fee.
Fees and timelines
Wandsworth 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 Wandsworth: planning: the council's own constraints map, validation checklist and pre-application service.
