Amersham, Buckinghamshire
Two-storey rear extension in Amersham
A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. If you live in Amersham and want to know what a two-storey rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
We cover Amersham (HP6 and HP7) as part of our Buckinghamshire work. Two-storey rear extensions suit semi-detached houses in Amersham best, where the extra bedroom matters as much as the bigger kitchen.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a two-storey rear extension cost in Amersham?
A two-storey rear extension in Amersham is priced at £2,020–£3,020 per square metre including VAT as a guide, before kitchen fit-out and fees. South East prices run above our West Midlands baseline, mainly on labour rates and clay-soil foundations.
| Size | Guide price inc VAT |
|---|---|
| 3 m × 5 m footprint, two floors (30 m²) | £60,500–£90,500 |
| 4 m × 6 m footprint, two floors (48 m²) | £97,000–£145,000 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a two-storey rear extension in Amersham?
Planning for a two-storey rear extension in Amersham follows the English householder rules.
A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Amersham like to extend?
Around Amersham the housing ranges from inter-war semis to 1960s and 1970s estates with good-sized gardens. Many of the newer estates had permitted development rights removed by condition, so we check the planning history before anything is drawn.
How a two-storey rear extension in Amersham comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Approvals
Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Two-storey rear extensions near Amersham
Neighbouring places we cover include Amersham on the Hill (0.7 miles) and Chesham (2.4 miles).
- Two-storey rear extension in Amersham on the Hill
- Two-storey rear extension in Chesham
- Two-storey rear extension in Beaconsfield
- Two-storey rear extension in Chorleywood
- Two-storey rear extension in Chalfont St Peter
Other work in Amersham:
FAQ
Two-storey rear extension questions in Amersham
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
Do I need planning permission for a rear extension in Amersham?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.
Will we need to move out?
Rarely. The first-floor opening is made late in the job and sealed with temporary screens.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.
How long does a rear extension take to build in Amersham?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.