Pitched roof extensions in High Wycombe: design, approvals and build
Our design and build teams take on pitched roof extensions in High Wycombe, from the first measured survey through planning and building control to the finished room.
- Guide price in High WycombeFrom £24,500 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsHP10, HP11, HP12, HP13, HP14

Guide prices for High Wycombe
Prices below are for High Wycombe, using the South East England factor of ×1.12. They are guide ranges including VAT for the build only, not a quote.
Typical rates in High Wycombe: £2,070 to £3,920 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £24,500 – £29,000 | £28,500 – £37,000 | £36,500 – £47,500 |
| 4 m × 5 m 20 m² | £41,000 – £48,500 | £48,000 – £62,000 | £61,500 – £78,500 |
| 5 m × 6 m 30 m² | £62,000 – £72,500 | £72,000 – £92,500 | £92,000 – £118,000 |
Try the guide-price tool to see a range for your own size and finish.
Extensions in and around High Wycombe
We cover High Wycombe and the postcode districts HP10, HP11, HP12, HP13, HP14, HP15. The same team covers Marlow (4 miles), Amersham (6 miles), Chesham (8 miles), Chalfont St Peter (8 miles), all within easy reach.
Just over the Berkshire border, Maidenhead is about 7 miles away. In the South East, plenty of houses have already been extended once, which makes checking the remaining permitted development allowance an important early step.
Is a pitched roof extension right for your house?
- Conservation-sensitive streets
- Homeowners who prefer a vaulted ceiling
- Traditional, period and rural houses
Matching tiles is harder than it sounds. We source reclaimed or closest-match tiles where the originals are no longer made and agree samples with you before ordering.
Planning rules that apply in High Wycombe
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.
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).
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
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
The build is managed from start to finish, inspected at each stage and signed off on completion.
Pitched roof extension questions answered
Do I need building regulations approval in High Wycombe?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for High Wycombe, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Who do I contract with for a pitched roof extension in High Wycombe?
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.
How much does a pitched roof extension cost?
Our guide range is about £2,070 to £3,920 per m² including VAT, a little more than a flat roof because of the roof structure and tiles.
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.
Book a free site visit in High Wycombe
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.