Pitched roof extensions in Keynsham
Keynsham homeowners can use us for the whole pitched roof extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in KeynshamFrom £22,500 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsBS31

Planning rules that apply in Keynsham
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.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
How much does a pitched roof extension cost in Keynsham?
Prices below are for Keynsham, using the South West England factor of ×1.02. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Keynsham: £1,890 to £3,570 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £22,500 – £26,500 | £26,000 – £34,000 | £33,500 – £43,000 |
| 4 m × 5 m 20 m² | £37,500 – £44,000 | £43,500 – £56,500 | £56,000 – £71,500 |
| 5 m × 6 m 30 m² | £56,500 – £66,000 | £65,500 – £84,500 | £84,000 – £107,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
Local to Keynsham
Our survey diary covers Keynsham, including BS31. Nearby, we also take on projects in Bath (6 miles), Nailsea (11 miles), Portishead (13 miles), Frome (15 miles).
Just over the Gloucestershire border, Kingswood is about 3 miles away. In the South West, local stone, render and brick vary from town to town, so matching materials is a big part of designing an extension that looks right.
What is included
- Lead or proprietary flashings to the main wall
- Roof design matched to the existing pitch and tiles
- Roof windows positioned for light and ventilation
- Vaulted ceilings or flat ceilings with storage above
- Insulation to current building regulations
What happens next
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 produce the drawings and structural design, and manage the approvals so they are in place before work starts.
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.
Pitched roof extension questions answered
Do you cover all of Keynsham?
Yes. We cover Keynsham and the surrounding parts of Somerset. Site visits are free and there is no obligation.
Who do I contract with for a pitched roof extension in Keynsham?
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.
Will my neighbours in Keynsham 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.
Is a pitched roof better than a flat roof?
Neither is better in all cases. Pitched roofs blend with traditional houses and shed water quickly; flat roofs give more headroom and suit modern designs and lanterns.
How much does a pitched roof extension cost?
Our guide range is about £1,890 to £3,570 per m² including VAT, a little more than a flat roof because of the roof structure and tiles.
Book a free site visit in Keynsham
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.