Timber frame extensions across Cornwall
We design and build timber frame extensions for houses in Cornwall, with a written price once the survey and design are done and one point of contact throughout.
- Guide priceFrom £21,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Towns covered9
- Site visitFree, no obligation
Will the council need to approve it?
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.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
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.
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).
Working in Cornwall
Towns we cover in Cornwall include Redruth, Falmouth, St Austell, Truro, Camborne, Newquay, Penzance, Bodmin. South West homes range from terraced streets in the cities to stone cottages and bungalows in the countryside, and conservation areas are common in historic centres.
How much does a timber frame extension cost in Cornwall?
These guide figures apply our South West England adjustment (×1.02) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Cornwall: £1,780 to £3,470 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £21,000 – £26,000 | £25,000 – £32,500 | £31,500 – £42,000 |
| 4 m × 5 m 20 m² | £35,500 – £43,000 | £41,500 – £54,500 | £53,000 – £69,500 |
| 5 m × 6 m 30 m² | £53,500 – £64,500 | £62,500 – £81,500 | £79,500 – £104,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
What we take care of
- Cladding, render or brick slip finish
- Frame design and structural calculations
- Foundations, often lighter than masonry
- Breathable wall build-up with insulation
- Fire and acoustic details where needed
How the project works
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
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions in Cornwall
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Cornwall, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Do you cover all of Cornwall?
Yes, across the whole of Cornwall. Site visits are free and there is no obligation.
Will my neighbours in Cornwall 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.
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 £1,780 to £3,470 per m² including VAT.
Book a free site visit in Cornwall
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.