Darwen, Lancashire
Two-storey rear extension in Darwen
Thinking about a two-storey rear extension in Darwen? A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
Darwen is covered from our Lancashire round, including BB1, BB2 and BB3. Two-storey rear extensions suit semi-detached houses in Darwen best, where the extra bedroom matters as much as the bigger kitchen.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a two-storey rear extension cost in Darwen?
For Darwen we work from the North West England rate: £1,690–£2,540 per square metre of new floor, including VAT, standard specification. North West prices sit below our West Midlands baseline; access on terraced streets is the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m × 5 m footprint, two floors (30 m²) | £51,000–£76,000 |
| 4 m × 6 m footprint, two floors (48 m²) | £81,000–£122,000 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a two-storey rear extension in Darwen?
Here is how the rules in England apply to a two-storey rear extension in Darwen.
England's rules allow a rear extension of more than one storey without an application only when it is no deeper than 3 metres and at least 7 metres from the boundary opposite the rear wall, and never on designated land. Most two-storey schemes need householder planning permission.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Darwen like to extend?
Stone and brick terraces are common around Darwen. Where houses back onto a ginnel or alley, deliveries can come in from the rear, which makes the build tidier.
How a two-storey rear extension in Darwen comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Approvals
Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Two-storey rear extensions near Darwen
Close by, we work in Blackburn, about 3.7 miles away, and Haslingden, about 5.8 miles away.
- Two-storey rear extension in Blackburn
- Two-storey rear extension in Haslingden
- Two-storey rear extension in Accrington
- Two-storey rear extension in Great Harwood
- Two-storey rear extension in Ramsbottom
Other work in Darwen:
FAQ
Two-storey rear extension questions in Darwen
Do you handle building control in Darwen?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
What is the 45-degree rule?
Many councils check that a two-storey extension does not cross a 45-degree line drawn from the nearest habitable window of the neighbouring house. We test it at the first drawing.
Is the site visit in Darwen free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Can you match the brick or stone on my Darwen house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.