Gainsborough, Lincolnshire
Side return extension in Gainsborough
Infilling the narrow passage beside a Victorian or Edwardian back addition. If you live in Gainsborough and want to know what a side return extension would cost and whether it needs planning, start with the online guide price or a free site visit.
Gainsborough sits in Lincolnshire, with postcode districts including DN21. In Gainsborough we check the boundary line and the neighbour's gutter before drawing a side return, because a few centimetres decide whether the wall goes on or beside the boundary.
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 Gainsborough?
For Gainsborough we work from the East Midlands rate: £2,230–£3,690 per square metre of new floor, including VAT, standard specification. East Midlands prices sit a little below our West Midlands baseline.
| Size | Guide price inc VAT |
|---|---|
| 2 m wide × 6 m deep (12 m²) | £27,000–£44,000 |
| 2.5 m wide × 7 m deep (17.5 m²) | £39,000–£64,500 |
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 Gainsborough?
Whether your side return extension in Gainsborough needs a planning application depends on its size, your house and any local restrictions.
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. At the first visit we measure what is there now and tell you which route fits: permitted development, prior approval or a planning application.
What are homes in Gainsborough like to extend?
Red-brick terraces and semis are typical of Gainsborough. Coal-mining legacy areas in parts of the East Midlands can need a Coal Authority check before foundations are designed.
How a side return extension in Gainsborough comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
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.
Side return extensions near Gainsborough
We also build side return extensions in nearby Retford (8.4 miles) and Scunthorpe (14.3 miles).
- Side return extension in Retford
- Side return extension in Scunthorpe
- Side return extension in Lincoln
- Side return extension in Boughton
- Side return extension in Worksop
Other work in Gainsborough:
FAQ
Side return extension questions in Gainsborough
How long does a rear extension take to build in Gainsborough?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Is the site visit in Gainsborough free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Do I need my neighbour's permission?
Not their permission, but in England and Wales you must serve party wall notices, and a neighbour can consent in writing or ask for a surveyor's award.
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
Do I need planning permission for a rear extension in Gainsborough?
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.
What postcode areas do you cover around Gainsborough?
Including DN21, and the surrounding Lincolnshire area.