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 St Austell?
In St Austell, a wraparound extension typically costs £2,250–£3,250 per m² of floor area, including VAT at 20% (standard rate). For a typical 28 m² project that is roughly £63,000–£91,000. Building costs in the South West are close to the UK average, so the figures for St Austell are close to our national guide. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (20 m²) | £45,000–£65,000 |
| Typical project (28 m²) | £63,000–£91,000 |
| Larger project (39 m²) | £88,000–£127,000 |
| Rate per m² | £2,250–£3,250 |
Your quote will depend mainly on:
- Drainage changes
- Kitchen and flooring specification
- Access for materials on terraced streets
- 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 St Austell?
The approval route for St Austell is set by planning law 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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
On a typical wraparound extension we handle:
- Underfloor heating option, electrics and plastering
- Building control completion
- Party wall notices and surveyor liaison
- Removal of internal and external walls
- Foundations and drainage
- Structural engineer’s design for steels and supports
How long does it take?
Allow 12 to 18 weeks on site. Design and approvals come first and typically take 3 to 4 months, depending on the approval route.
Building in St Austell
The South West mixes stone and render cottages with post-war and newer estates, and local materials matter more here when matching an extension.
St Austell sits in Cornwall, about 14 miles north-east of Truro. We cover the whole of St Austell, including postcodes PL25.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 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 St Austell
Is a wraparound worth it?
It gives the biggest ground-floor space without going upwards. Whether it adds value depends on your street and house, so we suggest checking local sale prices before committing.
How much does a wraparound extension cost in St Austell?
In St Austell, a wraparound extension typically costs £2,250–£3,250 per m² of floor area, including VAT at 20% (standard rate). A typical 28 m² project comes to roughly £63,000–£91,000. Your fixed price depends on the survey and drawings.
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.
Do you build wraparound extensions in St Austell?
Yes. We build wraparound extensions across St Austell, including postcodes PL25. Every project starts with a free home visit.
Can we keep a separate living room?
Yes. Many clients keep the front room separate and open up only the back of the house.
