Timber frame extensions in Darwen
A timber frame extension in Darwen starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in DarwenFrom £19,500 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time8–14 weeks on site
- Postcode districtsBB3

Covering Darwen
Our survey diary covers Darwen, including BB3. The same team covers Blackburn (4 miles), Accrington (6 miles), Chorley (7 miles), Rawtenstall (7 miles), all within easy reach.
Across the North West, terraced houses with small rear yards suit compact rear and side return extensions, while suburban semis have room for more.
What should I budget for a timber frame extension in Darwen?
Labour and material costs vary across the UK, so for Darwen we use our North West England factor (×0.95). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Darwen: £1,660 to £3,230 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £19,500 – £24,000 | £23,000 – £30,500 | £29,500 – £39,000 |
| 4 m × 5 m 20 m² | £33,000 – £40,000 | £38,500 – £50,500 | £49,000 – £65,000 |
| 5 m × 6 m 30 m² | £49,500 – £60,000 | £58,000 – £76,000 | £74,000 – £97,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
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.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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).
Who a timber frame extension suits
- Contemporary designs with timber or board cladding
- Sites where weight or speed matters
- Homeowners who want strong energy performance
Moisture is the enemy of any timber building. We design ventilated cladding cavities, breather membranes and a proper damp-proof course height, and keep the frame dry during construction.
Our process, step by step
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Questions people ask about timber frame extensions
How long does a timber frame extension take to build in Darwen?
On site, typically 8 to 14 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Who do I contract with for a timber frame extension in Darwen?
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.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Darwen, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
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 £1,660 to £3,230 per m² including VAT.
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.
Book a free site visit in Darwen
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.