Covering Blackburn
We work in Blackburn (BB1) and the places around it, including Darwen, Accrington and Chorley.
Homes in the North West
Terraced housing is a defining feature of many North West towns, which brings party walls and narrow access into most projects, with more space to extend on suburban semis.
What is included in a garden annexe in Blackburn?
We design annexes as permanent buildings with proper foundations, insulation and services, and we prepare the planning case showing how the annexe will be used as part of the main home. Connections for water, drainage and power are planned from the start.
- Foundations and drainage connections
- Kitchenette and shower room
- Accessible design options for older relatives
How much does a garden annexe cost in Blackburn?
What garden annexes typically cost. These are guide ranges; the written quote for your house replaces them.
| Garden annexes | Guide price incl. VAT |
|---|---|
| Standard specification | £2,400 to £2,900 per m² |
| Good specification | £2,900 to £3,400 per m² |
| High specification | £3,400 to £3,900 per m² |
How is a garden annexe approved in Blackburn?
In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it applies.
A self-contained annexe used for sleeping and living normally needs planning permission in England.
What can affect a garden annexe?
- A level threshold and wider doors make the annexe suitable for later life.
- Council tax treatment depends on who lives there; check with your council.
How does the project run?
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
Garden annexes: common questions
Can I rent the annexe out?
Usually not without a separate planning permission, because councils normally require it to stay part of the main house.
How long does an annexe take to build?
About 14 to 24 weeks on site after approvals.
Do you work in Blackburn?
Yes. Blackburn is within our coverage for garden annexes, along with nearby Darwen and Accrington.
Garden annexes near Blackburn
- Garden annexes in Darwen
- Garden annexes in Accrington
- Garden annexes in Chorley
- Garden annexes in Rawtenstall
Learn more about garden annexes, or see every project we cover in Blackburn.

