House extensions in Amersham
Every type of house extension in Amersham, from single-storey kitchen extensions to two-storey additions, side returns and orangeries. We design, handle the approvals and build.
- Postcode districtsHP6, HP7
- Price regionSouth East England (×1.12)
- Planning rulesEngland
- Site visitFree, no obligation
Areas we cover around Amersham
Our survey diary covers Amersham, including HP6, HP7. Neighbouring towns we cover include Chesham (2 miles), Chalfont St Peter (5 miles), Gerrards Cross (6 miles), High Wycombe (6 miles), Marlow (10 miles). Just over the Hertfordshire border, Rickmansworth is about 6 miles away.
Amersham extension prices at a glance
Every figure below is a guide for Amersham, adjusted for South East England build costs (×1.12) and including VAT. Design and council fees are shown separately on each page.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Extensions over a garage | 12 m² | £28,000 – £36,500 |
| Conservatory replacement extensions | 14 m² | £33,500 – £43,500 |
| Orangery extensions | 16 m² | £50,000 – £63,000 |
| Kitchen extensions | 20 m² | £47,000 – £59,500 |
| Double-storey extensions | 32 m² | £64,500 – £84,500 |
| Single-storey rear extensions | 20 m² | £45,500 – £58,500 |
Which extension suits a Amersham 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.
For many houses here, double-storey extensions, orangery extensions or wraparound extensions gives the most useful space for the budget.
Approvals for an extension in Amersham
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).
Every extension type in Amersham
- Single-storey rear extensions · from £23,500
- Annexe extensions · from £61,500
- Side extensions · from £24,500
- Building regulations for extensions · from £1,000
- Extensions over a garage · from £26,500
- Timber frame extensions · from £23,500
- Flat roof extensions · from £23,500
- Bedroom extensions · from £29,000
- Bungalow extensions · from £29,000
- Kitchen extensions · from £30,000
- Conservatory replacement extensions · from £22,000
- Planning permission for extensions · from £350
- Wraparound extensions · from £40,000
- Side return extensions · from £20,000
- Glass box extensions · from £33,500
- Orangery extensions · from £33,500
- Pitched roof extensions · from £24,500
- Double-storey extensions · from £42,500
- Home office extensions · from £17,500
- Utility and boot room extensions · from £15,500
- Extension plans and drawings · from £1,300
- Porch extensions · from £4,450
Free site visit
We visit your Amersham home, measure up, talk through what you want and check the planning position.
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
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
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 Amersham
How much does an extension cost in Amersham?
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.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for Amersham, and the guide-price tool gives a range for your own size and finish in about a minute.
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.
Do you cover all of Amersham?
Yes, including the surrounding parts of Buckinghamshire. Site visits are free and there is no obligation.
Book a free site visit in Amersham
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.