Wraparound extensions in Blackburn: design, approvals and build
Planning a wraparound extension in Blackburn? We survey the house, work out the planning route, draw the design and build it, so you deal with one team from the first visit to the completion certificate.
- Guide price in BlackburnFrom £34,000 inc VAT
- PlanningUsually a householder application
- Build time14–20 weeks on site
- Postcode districtsBB1, BB2, BB3, BB5, BB6
Planning rules that apply in Blackburn
In England a wraparound extension is assessed as both a side and a rear extension, and the combination usually falls outside permitted development, so most need a householder planning application (£548 from 1 April 2026).
The planning position for a specific Blackburn address depends on its history and any designations, which is why we check it at the first visit.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
Working in Blackburn
Our survey diary covers Blackburn, including BB1, BB2, BB3, BB5, BB6. Nearby, we also take on projects in Darwen (4 miles), Accrington (5 miles), Chorley (9 miles), Rawtenstall (9 miles).
Horwich, in Greater Manchester, is roughly 11 miles from Blackburn and also on our list. The North West has a high share of Victorian and Edwardian terraces with rear yards and outriggers, plus large areas of inter-war semis in the suburbs.
What we take care of
- Householder planning application
- Party wall notice support (England and Wales)
- Survey, design and 3D layout options
- Foundations, drainage and any manhole relocation
- Structural design for the corner and openings
The corner is where wraparounds succeed or fail. We usually use a single steel goalpost or a corner post hidden in a pier, and set the glazing so the new room reads as one space rather than two boxes.
What should I budget for a wraparound extension in Blackburn?
For Blackburn we adjust our national guide rates by ×0.95, the factor we use for North West England. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Blackburn: £1,900 to £3,520 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Compact L-shape 18 m² | £34,000 – £41,500 | £39,000 – £50,000 | £49,500 – £63,500 |
| Medium L-shape 25 m² | £47,500 – £57,000 | £54,500 – £69,000 | £68,500 – £88,000 |
| Large L-shape 32 m² | £60,500 – £73,000 | £69,500 – £88,500 | £88,000 – £112,500 |
Try the guide-price tool to see a range for your own size and finish.
What happens next
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Your questions about a wraparound extension in Blackburn
Do you cover all of Blackburn?
Yes. We cover Blackburn and the surrounding parts of Lancashire. Site visits are free and there is no obligation.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Blackburn, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Do I need building regulations approval in Blackburn?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Do wraparound extensions need planning permission?
Usually, yes. In England the side element counts as a side extension and the rear element as a rear extension, and the combination normally falls outside permitted development. A householder application costs £548 in England from 1 April 2026.
Will I need to move a drain?
Often. Side returns frequently contain a manhole or a shared drain. Building near or over a public sewer needs the water company’s consent in England and Wales, which we arrange.
Book a free site visit in Blackburn
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.