Darwen, Lancashire
Side return extension in Darwen
We plan and build side return extensions for homeowners in Darwen. Infilling the narrow passage beside a Victorian or Edwardian back addition. Start with a free site visit, then a written price once the design is agreed.
Darwen and its postcode districts BB1, BB2 and BB3 are part of our Lancashire coverage. Side return projects in Darwen usually start with a drainage survey of the side passage.
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 side return extension cost in Darwen?
Guide prices for a side return extension in Darwen start from our North West England rate of £2,160–£3,570 per square metre, including VAT. North West prices sit below our West Midlands baseline; access on terraced streets is the main variable.
| Size | Guide price inc VAT |
|---|---|
| 2 m wide × 6 m deep (12 m²) | £26,000–£43,000 |
| 2.5 m wide × 7 m deep (17.5 m²) | £38,000–£62,500 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a side return extension in Darwen?
Here is how the rules in England apply to a side return extension in Darwen.
Side return infills and the side leg of a wraparound are treated as side extensions in England: single-storey, no more than 4 metres high and no wider than half the original house. They are not permitted development in conservation areas, National Parks or National Landscapes, and a joined wraparound often needs a planning application because the side and rear rules apply together.
The Party Wall etc. Act 1996 applies in England: you serve notice two months before work to a shared wall, and one month before digging foundations within 3 metres (or 6 metres for deeper foundations) of a neighbour's building. Neighbours can agree in writing; if they dissent, surveyors agree an award.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Darwen like to extend?
Darwen has long runs of terraced houses with back yards and alleys, plus 1930s semis further out. Yard extensions on terraces are often single-storey and close to both boundaries.
How a side return 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.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
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.
Side return extensions near Darwen
Neighbouring places we cover include Blackburn (3.7 miles) and Haslingden (5.8 miles).
- Side return extension in Blackburn
- Side return extension in Haslingden
- Side return extension in Accrington
- Side return extension in Great Harwood
- Side return extension in Ramsbottom
Other work in Darwen:
FAQ
Side return 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.
How much space does a side return add?
Typically 8 to 18 square metres, enough to turn a galley kitchen into a kitchen-diner with an island.
How long does a rear extension take to build in Darwen?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Do I need planning permission for a rear extension in Darwen?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.
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.