Extending your home in Richmond
Looking to extend your home in Richmond? Start here: extension types, guide prices for Richmond, the planning rules that apply and how a project runs.
- Postcode districtsSW14, TW1, TW7, TW8, TW9, TW10
- Price regionLondon (×1.3)
- Planning rulesEngland
- Site visitFree, no obligation

Guide prices for Richmond
Prices on this page use our London factor of ×1.3, include VAT at 20% and cover the build; your written price follows a survey and agreed drawings.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Conservatory replacement extensions | 14 m² | £39,000 – £50,500 |
| Extensions over a garage | 12 m² | £32,500 – £42,500 |
| Side return extensions | 11 m² | £34,000 – £43,000 |
| Wraparound extensions | 25 m² | £74,500 – £94,500 |
| Double-storey extensions | 32 m² | £74,500 – £98,000 |
| Single-storey rear extensions | 20 m² | £53,000 – £68,000 |
| Kitchen extensions | 20 m² | £54,500 – £69,000 |
What works best for Richmond houses?
London's housing is dominated by Victorian and Edwardian terraces, many with a rear outrigger and a side return, and 1930s semis in the outer boroughs. Conservation areas are common, so the planning check comes first.
Start by comparing glass box extensions, kitchen extensions and side return extensions: between them they cover most of the layouts we see requested for houses like these.
Where we work near Richmond
Postcode districts we cover around Richmond include SW14, TW1, TW7, TW8, TW9, TW10. Neighbouring towns we cover include Isleworth (2 miles), Hounslow (2 miles), Barnes (3 miles), Roehampton (3 miles), Chiswick (3 miles). For homes towards Surrey, East Molesey is around 5 miles away.
Do extensions in Richmond need planning permission?
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Extension types and starting prices
- Flat roof extensions · from £27,000
- Bungalow extensions · from £34,000
- Side extensions · from £28,500
- Bedroom extensions · from £33,500
- Extensions over a garage · from £31,000
- Single-storey rear extensions · from £27,000
- Side return extensions · from £23,000
- Utility and boot room extensions · from £18,000
- Timber frame extensions · from £27,000
- Double-storey extensions · from £49,000
- Porch extensions · from £5,200
- Building regulations for extensions · from £1,150
- Kitchen extensions · from £35,000
- Annexe extensions · from £71,500
- Orangery extensions · from £39,000
- Planning permission for extensions · from £450
- Pitched roof extensions · from £28,500
- Wraparound extensions · from £46,500
- Glass box extensions · from £39,000
- Home office extensions · from £20,500
- Extension plans and drawings · from £1,550
- Conservatory replacement extensions · from £26,000
Free site visit
We visit your Richmond home, measure up, talk through what you want and check the planning position.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Questions about extensions in Richmond
How much does an extension cost in Richmond?
Using our London factor (×1.3), a standard-spec single-storey extension of 20 m² is a guide £53,000 to £68,000 including VAT, and a 32 m² two-storey extension £74,500 to £98,000. Your written price follows the survey.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
Who do I contract with?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
How long does an extension take in Richmond?
Usually 2 to 4 months of design and approvals, then 10 to 16 weeks on site for a single-storey extension or 16 to 24 weeks for two storeys.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for Richmond, and the guide-price tool gives a range for your own size and finish in about a minute.
Book a free site visit in Richmond
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.