Extensions in Blackburn: design, planning and build
Every type of house extension in Blackburn, from single-storey kitchen extensions to two-storey additions, side returns and orangeries. We design, handle the approvals and build.
- Postcode districtsBB1, BB2, BB3, BB5, BB6
- Price regionNorth West England (×0.95)
- Planning rulesEngland
- Site visitFree, no obligation
Choosing the right extension in Blackburn
Across the North West, terraced houses with small rear yards suit compact rear and side return extensions, while suburban semis have room for more.
For many houses here, side return extensions, single-storey rear extensions or kitchen extensions gives the most useful space for the budget.
What extensions cost in Blackburn
Use these Blackburn guide prices to sense-check a budget; the guide-price tool narrows them to your own size, and the site visit turns them into a written figure.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Double-storey extensions | 32 m² | £54,500 – £71,500 |
| Kitchen extensions | 20 m² | £39,500 – £50,500 |
| Side return extensions | 11 m² | £25,000 – £31,500 |
| Single-storey rear extensions | 20 m² | £38,500 – £49,500 |
| Extensions over a garage | 12 m² | £23,500 – £31,000 |
| Orangery extensions | 16 m² | £42,500 – £53,500 |
Where we work near Blackburn
Across BB1, BB2, BB3, BB5, BB6, we can visit, measure and advise. Neighbouring towns we cover include Darwen (4 miles), Accrington (5 miles), Chorley (9 miles), Rawtenstall (9 miles), Preston (9 miles). Horwich, in Greater Manchester, is roughly 11 miles from Blackburn and also on our list.
Planning rules in Blackburn
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In England a single-storey side return infill is often permitted development if it stays within the height limits and is no wider than half the width of the original house. Conservation areas, listed buildings and flats always need an application, and the boundary wall usually brings in the Party Wall Act.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Every extension type in Blackburn
- Orangery extensions · from £28,500
- Bungalow extensions · from £24,500
- Flat roof extensions · from £19,500
- Extension plans and drawings · from £1,100
- Timber frame extensions · from £19,500
- Home office extensions · from £15,000
- Planning permission for extensions · from £300
- Porch extensions · from £3,800
- Kitchen extensions · from £25,500
- Utility and boot room extensions · from £13,000
- Wraparound extensions · from £34,000
- Extensions over a garage · from £22,500
- Glass box extensions · from £28,500
- Building regulations for extensions · from £850
- Double-storey extensions · from £36,000
- Conservatory replacement extensions · from £19,000
- Single-storey rear extensions · from £19,500
- Annexe extensions · from £52,000
- Bedroom extensions · from £24,500
- Pitched roof extensions · from £21,000
- Side return extensions · from £17,000
- Side extensions · from £20,500
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Questions about extensions in Blackburn
How much does an extension cost in Blackburn?
Using our North West England factor (×0.95), a standard-spec single-storey extension of 20 m² is a guide £38,500 to £49,500 including VAT, and a 32 m² two-storey extension £54,500 to £71,500. Your written price follows the survey.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
Do you cover all of Blackburn?
Yes, including the surrounding parts of Lancashire. Site visits are free and there is no obligation.
How long does an extension take in Blackburn?
Usually 2 to 4 months of design and approvals, then 10 to 16 weeks on site for a single-storey extension or 16 to 24 weeks for two storeys.
Do I need planning permission for an extension in Blackburn?
Not always. It depends on the size, position and your property's history. Many single-storey rear extensions in England are permitted development or can use prior approval.
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.