Two-storey 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 two-storey extensions
A two-storey rear extension is permitted development only within tight limits: no more than 3 m deep, at least 7 m from the rear boundary, no higher than the existing house, eaves matching the existing eaves, materials similar in appearance, and any upper-floor side window obscure-glazed and non-opening below 1.7 m.
Most two-storey extensions exceed one of those limits, most often the 7 m rear boundary rule on London plots, so the usual route is a householder planning application. Flats have no permitted development rights.
What changes in Wandsworth
Extensions of more than one storey are not permitted development in a conservation area, so planning permission is always needed there.
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. Mansard lofts are widely accepted on terraces where they match a pattern already established on the street, but front dormers are resisted. 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.
