House Extension Drawings in Merton

Where in Merton does a house extension actually get determined?

Every Merton postcode district we draw in, the stock that dominates it and the authority that validates a house extension there. Merton fees below are the statutory England rates for 2026, not house extension estimates.

Which Merton neighbourhoods suit a house extension best?

Roof pitch, wall build-up and plot depth change every few Merton streets, and each one changes what a house extension can achieve at that address.

• Wimbledon (SW19, SW20) — a house extension in Wimbledon starts from victorian villas, edwardian terraces, and Wimbledon reads as Victorian villas, Edwardian terraces. The side-return infill is the classic move on these Victorian terraces — 3 m of permitted development depth plus the width of the original side passage in SW19. Merton Council assesses Wimbledon house extensions against its own Wimbledon character guidance, and the location plan we draw for Wimbledon references All England Club.
• Wimbledon Village (SW19) — a house extension in Wimbledon Village starts from georgian and victorian villas, and Wimbledon Village reads as Georgian and Victorian village conservation. Georgian rear elevations here are usually the listed or locally listed face of the building in SW19. Merton Council assesses Wimbledon Village house extensions against its own Wimbledon Village character guidance, and the location plan we draw for Wimbledon Village references Wimbledon Village High Street.
• Raynes Park (SW20) — house extension work in Raynes Park means 1930s semi-detached, edwardian terraces. Raynes Park is 1930s semi-detached, Edwardian terraces. Edwardian plots here are wider throughout SW20. Merton Council decides the Raynes Park application, and Raynes Park station anchors the Raynes Park location plan.
• Morden (SM4) — a house extension in Morden starts from 1930s semi-detached, post-war flats, and Morden reads as 1930s semi-detached, post-war flats. 1930s semis here have the deepest rear gardens in the area in SM4. Merton Council assesses Morden house extensions against its own Morden character guidance, and the location plan we draw for Morden references Morden Tube.
• Mitcham (CR4) — house extension work in Mitcham means 1930s semi-detached, post-war estates. Mitcham is 1930s semi-detached, post-war estates. 1930s semis here have the deepest rear gardens in the area throughout CR4. Merton Council decides the Mitcham application, and Mitcham Cricket Green anchors the Mitcham location plan.
• Colliers Wood (SW19) — Edwardian terraces, post-war flats defines Colliers Wood, where edwardian terraces, post-war flats set what a house extension can do. Edwardian plots here are wider across SW19. Any Colliers Wood house extension is validated by Merton Council, with Colliers Wood Tube the usual Colliers Wood reference point on the site plan.
• South Wimbledon (SW19) — Edwardian terraces defines South Wimbledon, where edwardian terraces set what a house extension can do. Edwardian plots here are wider across SW19. Any South Wimbledon house extension is validated by Merton Council, with South Wimbledon Tube the usual South Wimbledon reference point on the site plan.

How do conservation areas and Article 4 affect a house extension in Merton?

Merton conservation designations: there are 28 across Merton Council, Wimbledon Common, Wimbledon Village, John Innes among them. Designation costs a Merton owner the permitted-development route: a house extension then needs a £548 householder application over 8 weeks, in place of the £249 prior approval route that takes 6 weeks. Wimbledon Village is the Merton designation that most often changes a house extension design.

Article 4 and your Merton house extension: Merton Council has made no borough-wide direction, so permitted development for a house extension in Merton generally survives outside Merton conservation areas and listed curtilages. A Lawful Development Certificate at £274 is how a SW19 owner records that a house extension was lawful.

Merton housing stock: Victorian villas in Wimbledon; Edwardian terraces in Tooting and Colliers Wood; 1930s semi-detached in Morden and Raynes Park; post-war flats in Mitcham. Wimbledon is heavily conservation-controlled; outer Merton (Morden, Mitcham) is permissive. Read that before choosing a house extension route in Merton — construction, not postcode, sets what is achievable. Merton Council charges £548 for a householder application and has 8 weeks to determine it.

What happens if a Merton property sits on a boundary?

• Wandsworth — cross the Merton boundary and Wandsworth Council takes the house extension instead, applying 45 conservation areas of its own around SW8. We re-price house extensions at the Merton edge because Wandsworth policy and Merton policy rarely align on house extension depth.
• Lambeth — cross the Merton boundary and Lambeth Council takes the house extension instead, applying 64 conservation areas of its own around SE1. We re-price house extensions at the Merton edge because Lambeth policy and Merton policy rarely align on house extension depth.
• Croydon — the Croydon boundary runs against Merton, so a house extension a street from Merton is decided by Croydon Council instead. Croydon runs 24 conservation areas across CR0 and its neighbours, which is why house extensions priced for Merton are re-checked against Croydon policy whenever the Merton address sits on that edge.
• Sutton — cross the Merton boundary and Sutton Council takes the house extension instead, applying 17 conservation areas of its own around SM1. We re-price house extensions at the Merton edge because Sutton policy and Merton policy rarely align on house extension depth.

Sources for this Merton house extension page: borough policies maps and conservation-area registers (2025–26), Royal Mail postcode district boundaries, the Town and Country Planning (Fees for Applications) (England) Regulations, the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended, and the Party Wall etc. Act 1996.