Barnes timber frame extensions, designed and built
We design and build timber frame extensions for houses in Barnes, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in BarnesFrom £27,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time8–14 weeks on site
- Postcode districtsSW13, SW14, SW15, TW9, W4
How much does a timber frame extension cost in Barnes?
These guide figures apply our London adjustment (×1.3) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Barnes: £2,280 to £4,420 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £27,000 – £33,000 | £31,500 – £41,500 | £40,500 – £53,500 |
| 4 m × 5 m 20 m² | £45,500 – £55,000 | £53,000 – £69,000 | £67,500 – £88,500 |
| 5 m × 6 m 30 m² | £68,000 – £82,000 | £79,500 – £103,500 | £101,000 – £133,000 |
For a figure based on your own dimensions, use our guide-price tool.
Do I need planning permission in Barnes?
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 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.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
When a timber frame extension makes sense
- Homeowners who want strong energy performance
- Contemporary designs with timber or board cladding
- Sites where weight or speed matters
Extensions in and around Barnes
We cover Barnes and the postcode districts SW13, SW14, SW15, TW9, W4, W6. The same team covers Chiswick (1 mile), Roehampton (2 miles), Putney (2 miles), Fulham (2 miles), all within easy reach.
For homes towards Surrey, East Molesey is around 7 miles away. Across London, terraced houses with narrow side returns and tight access are the norm, which shapes everything from party wall notices to how materials reach the back garden.
From first visit to completion
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
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
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Timber frame extension questions answered
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Barnes, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Will my neighbours in Barnes be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Do I need building regulations approval in Barnes?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Does a timber frame extension need planning permission?
The same planning rules apply as for any extension. If the cladding looks different from the house, permitted development’s matching-materials condition may mean an application is needed.
Is timber frame cheaper than brick?
It is similar overall. The frame can save time on site, but the cladding choice has a big effect on cost. Our guide range is about £2,280 to £4,420 per m² including VAT.
Book a free site visit in Barnes
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.