Timber frame extensions across Northamptonshire
Northamptonshire homeowners can use us for the whole timber frame extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide priceFrom £19,500 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Towns covered9
- Site visitFree, no obligation

Towns in Northamptonshire
Do I need planning permission in Northamptonshire?
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.
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).
Timber frame extension prices in Northamptonshire
Prices below are for Northamptonshire, using the East Midlands factor of ×0.95. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Northamptonshire: £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.
Extensions in and around Northamptonshire
Towns we cover in Northamptonshire include Northampton, Corby, Kettering, Wellingborough, Rushden, Daventry, Market Harborough, Towcester. Homes across the East Midlands often have usable side land or a driveway beside the house, which opens up side and wraparound options.
Is a timber frame extension right for your house?
- Contemporary designs with timber or board cladding
- Sites where weight or speed matters
- Homeowners who want strong energy performance
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
We visit your Northamptonshire home, measure up, talk through what you want and check the planning position.
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
With the design and specification agreed, you get a fixed written price and a start date.
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
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Northamptonshire, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
How long does a timber frame extension take to build in Northamptonshire?
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 Northamptonshire?
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.
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 £1,660 to £3,230 per m² including VAT.
Book a free site visit in Northamptonshire
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.