Which postcode districts around Kingston upon Thames do we cover for basement extension work?
Every Kingston upon Thames postcode district we draw in, the stock that dominates
it and the authority that validates a basement extension there. Kingston upon Thames fees below are the
statutory England rates for 2026, not basement extension estimates.
| Postcode | Area | Dominant stock | What it means for a basement extension |
|---|
| KT1 | Kingston upon Thames | Georgian fragments, Victorian terraces, 1930s semi-detached | A basement extension at an KT1 address in Kingston upon Thames is determined by Kingston Council under its own Local Plan policies for Kingston upon Thames. |
| KT2 | Kingston / Norbiton | Georgian fragments, Victorian terraces, 1930s semi-detached | KT2 covers Kingston / Norbiton only; Kingston Council handles the basement extension. |
| KT3 | New Malden | Edwardian villas, 1930s semi-detached | KT3 covers New Malden only; Kingston Council handles the basement extension. |
| KT5 | Surbiton / Tolworth | Edwardian villas, mansion blocks | KT5 covers Surbiton / Tolworth only; Kingston Council handles the basement extension. |
| KT6 | Surbiton | Edwardian villas, mansion blocks | KT6 covers Surbiton only; Kingston Council handles the basement extension. |
| KT9 | Chessington | 1930s semi-detached | A basement extension at an KT9 address in Chessington is determined by Kingston Council under its own Local Plan policies for Chessington. |
Which Kingston upon Thames neighbourhoods suit a basement extension best?
Roof pitch, wall build-up and plot depth change every few Kingston upon Thames
streets, and each one changes what a basement extension can achieve at that address.
- Kingston (KT1, KT2) — basement extension work in Kingston means georgian fragments, victorian terraces, 1930s semi-detached. Kingston is Georgian and Victorian centre, riverside. Georgian houses here already have a vault and a lower-ground floor throughout KT1. Kingston Council decides the Kingston application, and Kingston Market anchors the Kingston location plan.
- Surbiton (KT5, KT6) — basement extension work in Surbiton means edwardian villas, mansion blocks. Surbiton is Edwardian villas, mansion blocks. Edwardian houses rarely have a usable cellar throughout KT5. Kingston Council decides the Surbiton application, and Surbiton station anchors the Surbiton location plan.
- New Malden (KT3) — basement extension work in New Malden means edwardian villas, 1930s semi-detached. New Malden is Edwardian villas, 1930s semi-detached. Edwardian houses rarely have a usable cellar throughout KT3. Kingston Council decides the New Malden application, and New Malden High Street anchors the New Malden location plan.
- Chessington (KT9) — 1930s semi-detached, post-war estates defines Chessington, where 1930s semi-detached set what a basement extension can do. 1930s houses were built without cellars across KT9. Any Chessington basement extension is validated by Kingston Council, with Chessington World of Adventures the usual Chessington reference point on the site plan.
- Tolworth (KT5, KT6) — basement extension work in Tolworth means 1930s semi-detached, post-war flats. Tolworth is 1930s semi-detached, post-war flats. 1930s houses were built without cellars throughout KT5. Kingston Council decides the Tolworth application, and Tolworth Tower anchors the Tolworth location plan.
- Norbiton (KT2) — Victorian terraces, Edwardian villas defines Norbiton, where victorian terraces, edwardian villas set what a basement extension can do. Victorian cellars here convert without planning permission when the footprint and external appearance are unchanged across KT2. Any Norbiton basement extension is validated by Kingston Council, with Norbiton station the usual Norbiton reference point on the site plan.
- Coombe (KT2, KT3) — a basement extension in Coombe starts from 1930s detached, edwardian villas, and Coombe reads as 1930s detached and large semi-detached. Edwardian houses rarely have a usable cellar in KT2. Kingston Council assesses Coombe basement extensions against its own Coombe character guidance, and the location plan we draw for Coombe references Coombe Hill.
What local planning policy applies to a basement extension in Kingston upon Thames?
How designation changes a Kingston upon Thames basement extension: Kingston Council maintains 22 conservation areas, including Coombe Hill, Kingston Old Town, Surbiton. Inside any of them a Kingston upon Thames basement extension cannot rely on permitted development, and the route becomes a £548 householder application determined in 8 weeks rather than a £249 prior approval in 6 weeks. Hampton Wick sets the tone for Kingston upon Thames casework.
Article 4 and your Kingston upon Thames basement extension: Kingston Council has made no borough-wide direction, so permitted development for a basement extension in Kingston upon Thames generally survives outside Kingston upon Thames conservation areas and listed curtilages. A Lawful Development Certificate at £274 is how a KT1 owner records that a basement extension was lawful.
What Kingston upon Thames is built from: Edwardian villas in Surbiton and New Malden; Victorian terraces in Kingston central; 1930s semi-detached in Chessington and Tolworth; post-war in New Malden. Outer south-west London suburban; generally permissive; riverside conservation areas add character in Kingston town. That mix decides the basement extension route in Kingston upon Thames more than the postcode does.
What happens if a Kingston upon Thames property sits on a boundary?
- Richmond upon Thames — adjoining Kingston upon Thames, with 72 conservation areas centred on SW13. A basement extension on the far side of the Kingston upon Thames line is determined by Richmond Council, so the Kingston upon Thames quote for basement extensions is checked against Richmond upon Thames guidance before it is issued.
- Merton — cross the Kingston upon Thames boundary and Merton Council takes the basement extension instead, applying 28 conservation areas of its own around SW16. We re-price basement extensions at the Kingston upon Thames edge because Merton policy and Kingston upon Thames policy rarely align on basement extension depth.
- Sutton — the Sutton boundary runs against Kingston upon Thames, so a basement extension a street from Kingston upon Thames is decided by Sutton Council instead. Sutton runs 17 conservation areas across SM1 and its neighbours, which is why basement extensions priced for Kingston upon Thames are re-checked against Sutton policy whenever the Kingston upon Thames address sits on that edge.
Sources for this Kingston upon Thames basement 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.
