Extending your home in High Wycombe
From a small utility to a two-storey addition, we take on house extensions throughout High Wycombe, starting with a free visit and a planning check.
- Postcode districtsHP10, HP11, HP12, HP13, HP14, HP15
- Price regionSouth East England (×1.12)
- Planning rulesEngland
- Site visitFree, no obligation
Where we work near High Wycombe
Across HP10, HP11, HP12, HP13, HP14, HP15, we can visit, measure and advise. We also work in nearby Marlow (4 miles), Amersham (6 miles), Chesham (8 miles), Chalfont St Peter (8 miles), Gerrards Cross (9 miles). For homes towards Berkshire, Maidenhead is around 7 miles away.
Which extension suits a High Wycombe home?
Homes across the South East range from Victorian terraces in the older town centres to large detached houses on the edges, so the right extension type varies street by street.
Depending on the plot, double-storey extensions and orangery extensions are often the strongest options, with single-storey rear extensions worth considering where there is room.
Planning rules 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 England a single-storey side return infill is often permitted development if it stays within the height limits and is no wider than half the width of the original house. Conservation areas, listed buildings and flats always need an application, and the boundary wall usually brings in the Party Wall Act.
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).
Guide prices for High Wycombe
Prices on this page use our South East England factor of ×1.12, include VAT at 20% and cover the build; your written price follows a survey and agreed drawings.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Wraparound extensions | 25 m² | £64,000 – £81,500 |
| Double-storey extensions | 32 m² | £64,500 – £84,500 |
| Kitchen extensions | 20 m² | £47,000 – £59,500 |
| Single-storey rear extensions | 20 m² | £45,500 – £58,500 |
| Extensions over a garage | 12 m² | £28,000 – £36,500 |
| Orangery extensions | 16 m² | £50,000 – £63,000 |
Choose an extension type
- Building regulations for extensions · from £1,000
- Conservatory replacement extensions · from £22,000
- Glass box extensions · from £33,500
- Timber frame extensions · from £23,500
- Annexe extensions · from £61,500
- Bungalow extensions · from £29,000
- Kitchen extensions · from £30,000
- Side extensions · from £24,500
- Home office extensions · from £17,500
- Extension plans and drawings · from £1,300
- Utility and boot room extensions · from £15,500
- Double-storey extensions · from £42,500
- Wraparound extensions · from £40,000
- Side return extensions · from £20,000
- Flat roof extensions · from £23,500
- Single-storey rear extensions · from £23,500
- Pitched roof extensions · from £24,500
- Bedroom extensions · from £29,000
- Orangery extensions · from £33,500
- Porch extensions · from £4,450
- Extensions over a garage · from £26,500
- Planning permission for extensions · from £350
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
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Questions about extensions in High Wycombe
How much does an extension cost in High Wycombe?
Using our South East England factor (×1.12), a standard-spec single-storey extension of 20 m² is a guide £45,500 to £58,500 including VAT, and a 32 m² two-storey extension £64,500 to £84,500. Your written price follows the survey.
Do you cover all of High Wycombe?
Yes, including the surrounding parts of Buckinghamshire. Site visits are free and there is no obligation.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for High Wycombe, and the guide-price tool gives a range for your own size and finish in about a minute.
Who do I contract with?
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.
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.