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 Blackburn?
In Blackburn, a wraparound extension typically costs £2,050–£3,000 per m² of floor area, including VAT at 20% (standard rate). For a typical 28 m² project that is roughly £57,500–£84,000. The guide for Blackburn reflects typical costs in the North West, roughly 6% below the UK-wide figure. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (20 m²) | £41,000–£60,000 |
| Typical project (28 m²) | £57,500–£84,000 |
| Larger project (39 m²) | £80,000–£117,000 |
| Rate per m² | £2,050–£3,000 |
What moves the price most:
- Drainage changes
- Steelwork and propping of the existing house
- Kitchen and flooring specification
- Party wall surveyor fees for one or both neighbours
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 Blackburn?
Here is how the rules work for a wraparound extension 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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
From survey to sign-off, the job normally involves:
- Foundations and drainage
- Removal of internal and external walls
- Design and planning application
- Party wall notices and surveyor liaison
- Walls, roof and glazing
- Building control completion
How long does it take?
The build itself usually takes 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 Blackburn
The North West has many brick terraces and inter-war semis, where kitchen extensions and dormer loft conversions add space without moving.
Our Blackburn coverage includes postcode districts BB1, and we also work in nearby places such as Darwen, Accrington and Chorley.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 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 Blackburn
How long does a wraparound extension take in Blackburn?
Typically 12 to 18 weeks on site. Design and approvals beforehand usually take 3 to 4 months.
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.
How much does a wraparound extension cost in Blackburn?
In Blackburn, a wraparound extension typically costs £2,050–£3,000 per m² of floor area, including VAT at 20% (standard rate). A typical 28 m² project comes to roughly £57,500–£84,000. 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.
What about the old back addition?
The side wall of the back addition is usually removed and replaced with a steel beam, so the old kitchen joins the new space.