Two-storey extensions in Blackburn
We design, get approval for and build two-storey extensions in Blackburn and the surrounding area. Choose the type of extension below or book a free site visit.
Blackburn at a glance
- Postcode districts
- BB1 and BB2
- Area
- Lancashire, England
- Price region
- North West England
- Nearest towns
- Darwen (3.7 miles), Great Harwood (3.9 miles), Accrington (5.1 miles), Haslingden (7.3 miles)
- Distance to Preston
- about 9.1 miles
- Approvals
- Two-storey rear: up to 3 m deep and 7 m from the rear boundary under permitted development. Side, wraparound and front: planning permission.
We cover Blackburn (BB1 and BB2) and the places around it, including Darwen (3.7 miles), Great Harwood (3.9 miles) and Accrington.
Extensions available in Blackburn
Two-storey rear extensions
Design, approvals and build for Blackburn homes. Guide from £53,000.
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Two-storey side extensions
Blackburn guide price from £82,000, Standard spec.
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Two-storey wraparound extensions
Design, approvals and build for Blackburn homes. Guide from £114,500.
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Part single, part two-storey extensions
For homes in Blackburn: typical guide from £68,500.
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Extensions over a garage
From £30,000 in Blackburn. Free visit to firm it up.
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First-floor extensions
Design, approvals and build for Blackburn homes. Guide from £24,000.
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Two-storey extensions for semi-detached houses
Guide from £53,000 in Blackburn, including VAT.
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Two-storey extensions for detached houses
Our North West England guide starts at £82,000 for this type.
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Kitchen extensions with bedrooms above
For homes in Blackburn: typical guide from £53,000 (before kitchen units).
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Extra bedroom and en-suite extensions
Our North West England guide starts at £53,000 (plus en-suite) for this type.
Learn moreWhich type suits your house?
If you're not sure which type fits, that's what the free visit is for. We'll sketch the realistic options for your house in Blackburn, with a rough idea of the approval route and cost for each.
Also available in Lancashire
- Two-storey front extensions
- Two-storey extensions for end-of-terrace houses
- Two-storey annexe extensions
- Garage conversions with a room above
- Two-storey extension plans and drawings
- Planning permission for two-storey extensions
- Structural engineering for two-storey extensions
- Building regulations for two-storey extensions
- Party wall notices for extensions
- Design and build two-storey extensions
Rules for Blackburn
Blackburn is in England. Two-storey rear: up to 3 m deep and 7 m from the rear boundary under permitted development. Side, wraparound and front: planning permission. Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.
The full England rules explained
Questions about extensions in Blackburn
Do you cover Blackburn?
Yes. We cover Blackburn (BB1 and BB2) and the surrounding area, including Darwen and Great Harwood. The first site visit is free.
What does a two-storey extension cost in Blackburn?
Using our North West England guide, a two-storey rear extension with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) is about £53,000–£72,000 including VAT. An extension over a garage is about £30,000–£43,500.
Which other places near Blackburn do you cover?
Everywhere around it, including Darwen (3.7 miles), Great Harwood (3.9 miles) and Accrington (5.1 miles), and the rest of Lancashire.