What is a wraparound extension?
A wraparound extension combines a side return and a rear extension into one L-shaped addition. It gives the largest possible ground floor, often creating an open-plan kitchen, dining and living space across the whole width of the house.
How much does a wraparound extension cost in Amersham?
In Amersham, a wraparound extension typically costs £2,450–£3,600 per m² of floor area, including VAT at 20% (standard rate). For a typical 28 m² project that is roughly £68,500–£101,000. Prices across the South East are typically 12% above the UK average for this kind of work, which is reflected in the range for Amersham. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (20 m²) | £49,000–£72,000 |
| Typical project (28 m²) | £68,500–£101,000 |
| Larger project (39 m²) | £95,500–£140,500 |
| Rate per m² | £2,450–£3,600 |
The main things that change the cost:
- Total footprint and the amount of glazing
- Steelwork and propping of the existing house
- Party wall surveyor fees for one or both neighbours
- Kitchen and flooring specification
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a wraparound extension in Amersham?
Approvals for a wraparound extension in Amersham follow the rules for England. In England a wraparound extension combines side and rear elements, which normally takes it outside permitted development, so a householder planning application is made.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
The work we manage on a wraparound extension:
- Foundations and drainage
- Party wall notices and surveyor liaison
- Building control completion
- Underfloor heating option, electrics and plastering
- Removal of internal and external walls
- Design and planning application
How long does it take?
Build time is typically 12 to 18 weeks on site. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Amersham
Commuter towns across the South East have many 1930s and post-war semis that suit rear extensions and hip-to-gable loft conversions.
From HP7 outwards, we take on projects throughout Amersham and the surrounding parts of Buckinghamshire.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about wraparound extensions in Amersham
How much does a wraparound extension cost in Amersham?
In Amersham, a wraparound extension typically costs £2,450–£3,600 per m² of floor area, including VAT at 20% (standard rate). A typical 28 m² project comes to roughly £68,500–£101,000. Your fixed price depends on the survey and drawings.
How long does it take to build?
Around 12 to 18 weeks on site after approvals. Design, planning and party wall matters usually take 3 to 4 months beforehand.
Can we keep a separate living room?
Yes. Many clients keep the front room separate and open up only the back of the house.
Do you build wraparound extensions in Amersham?
Yes. We build wraparound extensions across Amersham, including postcodes HP7. Every project starts with a free home visit.
Will both neighbours be affected?
Usually only the neighbour on the side return side, but rear foundations near either boundary can trigger party wall notices.