Side return extensions in Gainsborough
Planning a side return extension in Gainsborough? We survey the house, work out the planning route, draw the design and build it, so you deal with one team from the first visit to the completion certificate.
- Guide price in GainsboroughFrom £17,000 inc VAT
- PlanningOften permitted development; party wall notice usual
- Build time10–14 weeks on site
- Postcode districtsDN21
Will the council need to approve it?
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.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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).
Local to Gainsborough
We cover Gainsborough and the postcode districts DN21. The same team covers Scunthorpe (14 miles), Lincoln (14 miles), Grimsby (31 miles), Cleethorpes (33 miles), all within easy reach.
Just over the Nottinghamshire border, Retford is about 8 miles away. The East Midlands has plenty of inter-war and post-war semis and detached houses with room to extend, alongside Victorian terraces in the towns.
When a side return extension makes sense
- Narrow galley kitchens
- Victorian and Edwardian terraces with a rear outrigger
- Homes where the garden is too small to lose much depth
Light is the design problem. A side return can make the middle of the house darker if the roof is solid, so we model the daylight and usually recommend a glazed slope or a run of rooflights along the boundary edge.
What should I budget for a side return extension in Gainsborough?
Labour and material costs vary across the UK, so for Gainsborough we use our East Midlands factor (×0.95). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Gainsborough: £2,000 to £3,610 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 1.8 m × 4.5 m 8 m² | £17,000 – £20,500 | £18,000 – £23,000 | £22,500 – £29,000 |
| 2 m × 5.5 m 11 m² | £21,500 – £26,500 | £25,000 – £31,500 | £31,000 – £40,000 |
| 2.2 m × 7 m 15 m² | £29,500 – £36,000 | £34,000 – £43,000 | £42,500 – £54,500 |
Try the guide-price tool to see a range for your own size and finish.
From first visit to completion
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Questions people ask about side return extensions
How long does a side return extension take to build in Gainsborough?
On site, typically 10 to 14 weeks once approvals are in place. Before that, allow 6–12 weeks design and approvals.
Do you cover all of Gainsborough?
Yes. We cover Gainsborough and the surrounding parts of Lincolnshire. Site visits are free and there is no obligation.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Gainsborough, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Can I combine a side return with a rear extension?
Yes. That combination is a wraparound extension, which adds the most space to a terraced house.
How much does a side return extension cost?
Our guide range is about £2,000 to £3,610 per m² including VAT, so a typical 2 m × 5.5 m infill lands around £25,000 to £31,500 at standard spec in Gainsborough, more in London.
Book a free site visit in Gainsborough
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.