Home extensions in Chesham
Planning an extension in Chesham? Compare extension types, see guide prices adjusted for Chesham and book a free site visit.
- Postcode districtsHP5, HP6
- Price regionSouth East England (×1.12)
- Planning rulesEngland
- Site visitFree, no obligation
Where we work near Chesham
Our survey diary covers Chesham, including HP5, HP6. The same team covers Amersham (2 miles), Chalfont St Peter (7 miles), High Wycombe (8 miles), Gerrards Cross (8 miles), Marlow (12 miles), all within easy reach. For homes towards Hertfordshire, Berkhamsted is around 4 miles away.
Approvals for an extension in Chesham
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).
Chesham extension prices at a glance
Use these Chesham 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 |
| Extensions over a garage | 12 m² | £28,000 – £36,500 |
| Kitchen extensions | 20 m² | £47,000 – £59,500 |
| Double-storey extensions | 32 m² | £64,500 – £84,500 |
Choosing the right extension in Chesham
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.
For many houses here, orangery extensions, single-storey rear extensions or wraparound extensions gives the most useful space for the budget.
Every extension type in Chesham
- Orangery extensions · from £33,500
- Single-storey rear extensions · from £23,500
- Double-storey extensions · from £42,500
- Porch extensions · from £4,450
- Bungalow extensions · from £29,000
- Glass box extensions · from £33,500
- Kitchen extensions · from £30,000
- Planning permission for extensions · from £350
- Pitched roof extensions · from £24,500
- Timber frame extensions · from £23,500
- Side return extensions · from £20,000
- Wraparound extensions · from £40,000
- Annexe extensions · from £61,500
- Building regulations for extensions · from £1,000
- Home office extensions · from £17,500
- Utility and boot room extensions · from £15,500
- Conservatory replacement extensions · from £22,000
- Flat roof extensions · from £23,500
- Extensions over a garage · from £26,500
- Bedroom extensions · from £29,000
- Side extensions · from £24,500
- Extension plans and drawings · from £1,300
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
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
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions about extensions in Chesham
How much does an extension cost in Chesham?
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.
Do you cover all of Chesham?
Yes, including the surrounding parts of Buckinghamshire. Site visits are free and there is no obligation.
Will my neighbours need to be told?
If you apply for planning or prior approval the council notifies them, and in England party wall notices may be needed for work near a shared boundary.
Book a free site visit in Chesham
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.