Timber frame extensions across Dorset
If you live in Dorset and want more space without moving, a timber frame extension is one of the most practical ways to get it. We handle the drawings, approvals and the build.
- 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

Towns in Dorset
Guide prices for Dorset
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 Dorset: £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 |
For a figure based on your own dimensions, use our guide-price tool.
When a timber frame extension makes sense
- Homeowners who want strong energy performance
- Sites where weight or speed matters
- Contemporary designs with timber or board cladding
Covering Dorset
Towns we cover in Dorset include Bournemouth, Poole, Weymouth, Christchurch, Dorchester, Wimborne Minster, Bridport, Ferndown. 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.
Do I need planning permission in Dorset?
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.
The planning position for a specific Dorset address depends on its history and any designations, which is why we check it at the first visit.
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).
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
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
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Timber frame extension questions answered
Do I need building regulations approval in Dorset?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Do you cover all of Dorset?
Yes, across the whole of Dorset. Site visits are free and there is no obligation.
Will my neighbours in Dorset 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 Dorset
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.