Home extensions in Gerrards Cross
From a small utility to a two-storey addition, we take on house extensions throughout Gerrards Cross, starting with a free visit and a planning check.
- Postcode districtsSL9
- Price regionSouth East England (×1.12)
- Planning rulesEngland
- Site visitFree, no obligation
Planning rules in Gerrards Cross
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 two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
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.
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).
Choosing the right extension in Gerrards Cross
The South East has a broad mix of 1930s semis, post-war estates, newer developments and period cottages, and many houses have enough garden for a generous rear extension.
The types we would usually look at first for a home in Gerrards Cross are double-storey extensions, wraparound extensions and orangery extensions, depending on the garden and how the house is laid out.
What extensions cost in Gerrards Cross
Use these Gerrards Cross guide prices to sense-check a budget; the guide-price tool narrows them to your own size, and the site visit turns them into a written figure.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Wraparound extensions | 25 m² | £64,000 – £81,500 |
| Orangery extensions | 16 m² | £50,000 – £63,000 |
| Kitchen extensions | 20 m² | £47,000 – £59,500 |
| Single-storey rear extensions | 20 m² | £45,500 – £58,500 |
| Side return extensions | 11 m² | £29,500 – £37,000 |
| Conservatory replacement extensions | 14 m² | £33,500 – £43,500 |
| Double-storey extensions | 32 m² | £64,500 – £84,500 |
Areas we cover around Gerrards Cross
We cover Gerrards Cross and the postcode districts SL9. Nearby, we also take on projects in Chalfont St Peter (2 miles), Amersham (6 miles), Chesham (8 miles), High Wycombe (9 miles), Marlow (9 miles). For homes towards Greater London, Uxbridge is around 4 miles away.
Extension types and starting prices
- Bedroom extensions · from £29,000
- Conservatory replacement extensions · from £22,000
- Single-storey rear extensions · from £23,500
- Flat roof extensions · from £23,500
- Timber frame extensions · from £23,500
- Extensions over a garage · from £26,500
- Extension plans and drawings · from £1,300
- Bungalow extensions · from £29,000
- Orangery extensions · from £33,500
- Pitched roof extensions · from £24,500
- Building regulations for extensions · from £1,000
- Home office extensions · from £17,500
- Double-storey extensions · from £42,500
- Kitchen extensions · from £30,000
- Annexe extensions · from £61,500
- Glass box extensions · from £33,500
- Utility and boot room extensions · from £15,500
- Side extensions · from £24,500
- Side return extensions · from £20,000
- Planning permission for extensions · from £350
- Wraparound extensions · from £40,000
- Porch extensions · from £4,450
Free site visit
We visit your Gerrards Cross home, measure up, talk through what you want and check the planning position.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
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 Gerrards Cross
How much does an extension cost in Gerrards Cross?
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.
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.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for Gerrards Cross, and the guide-price tool gives a range for your own size and finish in about a minute.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
Do you cover all of Gerrards Cross?
Yes, including the surrounding parts of Buckinghamshire. Site visits are free and there is no obligation.
Book a free site visit in Gerrards Cross
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.