Single-storey rear extensions across Towcester
A single-storey extension in Towcester 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 TowcesterFrom £19,500 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsNN12

Planning rules that apply in Towcester
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.
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).
Local to Towcester
Our survey diary covers Towcester, including NN12. We also work in nearby Brackley (9 miles), Northampton (10 miles), Daventry (11 miles), Wellingborough (18 miles).
Homes across the East Midlands often have usable side land or a driveway beside the house, which opens up side and wraparound options.
Who a single-storey extension suits
- Terraced houses that want a deeper kitchen across the full width
- Homeowners who want open-plan living onto the garden
- Semi-detached and detached houses with a usable rear garden
Guide prices for Towcester
These guide figures apply our East Midlands adjustment (×0.95) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Towcester: £1,660 to £3,230 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £19,500 – £23,500 | £23,000 – £30,000 | £29,500 – £39,000 |
| 4 m × 5 m 20 m² | £33,000 – £39,000 | £38,500 – £49,500 | £49,000 – £65,000 |
| 5 m × 6 m 30 m² | £49,500 – £58,500 | £58,000 – £74,500 | £74,000 – £97,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
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
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
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.
Common questions in Towcester
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Towcester, 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 Towcester 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 Towcester?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
How much does a single-storey extension cost per square metre?
Our guide range is about £1,660 to £3,230 per m² including VAT, depending on specification. A standard-spec 4 m × 5 m room usually lands at £38,500 to £49,500 in Towcester, plus design and council fees.
How deep can a single-storey rear extension be without planning permission?
In England, up to 3 m beyond the original rear wall on a semi-detached or terraced house and 4 m on a detached house, within height and boundary limits. Through the larger home extension prior approval scheme those depths rise to 6 m and 8 m. Wales, Scotland and Northern Ireland use their own rules, which we check for your address.
Book a free site visit in Towcester
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.