Amersham wraparound extensions, designed and built
We design and build wraparound extensions for houses in Amersham, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in AmershamFrom £40,000 inc VAT
- PlanningUsually a householder application
- Build time14–20 weeks on site
- Postcode districtsHP6, HP7
Planning and approvals in Amersham
In England a wraparound extension is assessed as both a side and a rear extension, and the combination usually falls outside permitted development, so most need a householder planning application (£548 from 1 April 2026).
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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).
Guide prices for Amersham
Prices below are for Amersham, 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 Amersham: £2,240 to £4,140 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Compact L-shape 18 m² | £40,000 – £48,500 | £46,000 – £58,500 | £58,000 – £75,000 |
| Medium L-shape 25 m² | £56,000 – £67,500 | £64,000 – £81,500 | £81,000 – £104,000 |
| Large L-shape 32 m² | £71,500 – £86,500 | £82,000 – £104,000 | £103,500 – £133,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Extensions in and around Amersham
Across HP6, HP7, we can visit, measure and advise. Nearby, we also take on projects in Chesham (2 miles), Chalfont St Peter (5 miles), Gerrards Cross (6 miles), High Wycombe (6 miles).
Rickmansworth, in Hertfordshire, is roughly 6 miles from Amersham and also on our list. In the South East, plenty of houses have already been extended once, which makes checking the remaining permitted development allowance an important early step.
What is included
- Roof with glazing along the side return
- Full internal finish or kitchen-ready shell
- Householder planning application
- Structural design for the corner and openings
- Foundations, drainage and any manhole relocation
Our process, step by step
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
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.
Your questions about a wraparound extension in Amersham
Do I need building regulations approval in Amersham?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
How long does a wraparound extension take to build in Amersham?
On site, typically 14 to 20 weeks once approvals are in place. Before that, allow 8–16 weeks design and approvals.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Amersham, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Do wraparound extensions need planning permission?
Usually, yes. In England the side element counts as a side extension and the rear element as a rear extension, and the combination normally falls outside permitted development. A householder application costs £548 in England from 1 April 2026.
How much does a wraparound extension cost?
Our guide range is about £2,240 to £4,140 per m² including VAT. A 25 m² standard-spec wraparound typically lands around £64,000 to £81,500 in Amersham before design and council fees.
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.