Penzance pitched roof extensions, designed and built
A pitched roof extension in Penzance 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 PenzanceFrom £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 districtsTR18

Planning rules that apply in Penzance
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.
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).
Included in a typical project
- Insulation to current building regulations
- Roof windows positioned for light and ventilation
- Lead or proprietary flashings to the main wall
- Vaulted ceilings or flat ceilings with storage above
- Roof design matched to the existing pitch and tiles
Pitched roof extension prices in Penzance
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 Penzance: £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 |
Try the guide-price tool to see a range for your own size and finish.
Local to Penzance
Our survey diary covers Penzance, including TR18. The same team covers Camborne (12 miles), Redruth (16 miles), Falmouth (21 miles), Truro (24 miles), all within easy reach.
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.
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
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
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
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Penzance, 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 Penzance 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.
Who do I contract with for a pitched roof extension in Penzance?
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 have a vaulted ceiling?
Yes. A vaulted ceiling with roof windows is one of the main reasons to choose a pitched roof. It needs insulation between and under the rafters to meet the building regulations.
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 Penzance
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.