Single-storey extensions in Blackburn

Covering Blackburn

Blackburn sits 9 miles east of Preston, with Darwen 4 miles to the south and Accrington 5 miles to the east.

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 does a single-storey extension involve?

We design the extension around how you use the house: where the light comes from, how the new room joins the old one, and what happens to the drains and the garden. The structure is built in brick or block to match the house, finished with a flat roof and lantern or a pitched roof, then insulated, plastered and handed back ready to decorate.

Measured survey and design drawings
Brickwork, roof, glazing and insulation
First-fix and second-fix electrics, plastering and making good

What will a single-storey extension cost?

What single-storey extensions typically cost. These are guide ranges; the written quote for your house replaces them.

Single-storey extensions	Guide price incl. VAT
Standard specification	£2,600 to £3,000 per m²
Good specification	£3,000 to £3,500 per m²
High specification	£3,500 to £4,000 per m²

What approvals does a single-storey extension need in England?

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.

In England a single-storey rear extension can often go ahead under permitted development: up to 3 m deep on an attached house or 4 m on a detached one, no higher than 4 m, with eaves no higher than 3 m within 2 m of a boundary. Deeper extensions, up to 6 m or 8 m, need prior approval from the council first.

What can change the price or programme?

Drains under the footprint may need diverting or a build-over agreement with the water company.
Kitchens and doors have long lead times, so we order them early.

How does the project run?

Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

Questions about a single-storey extension in Blackburn

How much does a single-storey extension cost?

Most single-storey extensions cost about £2,600 to £4,000 per square metre including VAT, depending on specification, glazing and ground conditions. We give a fixed price in writing for the agreed specification after the survey.

Do you need to dig up the drains?

Sometimes. If a public sewer runs under the extension, the water company has to agree a build-over or a diversion. We check this at survey stage.

Do you work in Blackburn?

Yes. Blackburn is within our coverage for single-storey extensions, along with nearby Darwen and Accrington.

Also covering

Learn more about single-storey extensions, or see every project we cover in Blackburn.