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 Berkhamsted?
In Berkhamsted, a wraparound extension typically costs £2,350–£3,400 per m² of floor area, including VAT at 20% (standard rate). For a typical 28 m² project that is roughly £66,000–£95,000. That range is adjusted for the East of England, where domestic building work typically costs around 6% above the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (20 m²) | £47,000–£68,000 |
| Typical project (28 m²) | £66,000–£95,000 |
| Larger project (39 m²) | £91,500–£132,500 |
| Rate per m² | £2,350–£3,400 |
Your quote will depend mainly on:
- Drainage changes
- Access for materials on terraced streets
- Steelwork and propping of the existing house
- Party wall surveyor fees for one or both neighbours
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a wraparound extension in Berkhamsted?
Whether you need planning permission depends on your house and its location in 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
On a typical wraparound extension we handle:
- Removal of internal and external walls
- Foundations and drainage
- Structural engineer’s design for steels and supports
- Walls, roof and glazing
- Party wall notices and surveyor liaison
- Underfloor heating option, electrics and plastering
How long does it take?
Expect 12 to 18 weeks on site. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Berkhamsted
Across the East of England, 1930s and post-war semis, newer estates and rural cottages all feature, each with different extension and loft options.
From HP4 outwards, we take on projects throughout Berkhamsted and the surrounding parts of Hertfordshire.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about wraparound extensions in Berkhamsted
How much does a wraparound extension cost in Berkhamsted?
In Berkhamsted, a wraparound extension typically costs £2,350–£3,400 per m² of floor area, including VAT at 20% (standard rate). A typical 28 m² project comes to roughly £66,000–£95,000. Your fixed price depends on the survey and drawings.
Do you build wraparound extensions in Berkhamsted?
Yes. We build wraparound extensions across Berkhamsted, including postcodes HP4. Every project starts with a free home visit.
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.
Does a wraparound extension need planning permission?
Almost always. Combining side and rear elements usually goes beyond permitted development limits, so a householder planning application is normally made.
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.
