Side return extensions in Durham: design, approvals and build
A side return extension in Durham starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in DurhamFrom £16,000 inc VAT
- PlanningOften permitted development; party wall notice usual
- Build time10–14 weeks on site
- Postcode districtsDH1
Planning rules that apply in Durham
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.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
Covering Durham
We cover Durham and the postcode districts DH1. The same team covers Chester-le-Street (6 miles), Stanley (8 miles), Bishop Auckland (9 miles), Peterlee (10 miles), all within easy reach.
Houghton-le-Spring, in Tyne and Wear, is roughly 6 miles from Durham and also on our list. Across the North East, houses often have rear yards or modest gardens, so compact, well-lit single-storey extensions make the biggest difference.
What is included
- Design to keep daylight in the middle of the house
- Removal of the side wall and new steelwork
- Party wall notice support (England and Wales)
- New boundary wall or raised party wall
How much does a side return extension cost in Durham?
These guide figures apply our North East England adjustment (×0.91) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Durham: £1,910 to £3,460 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 1.8 m × 4.5 m 8 m² | £16,000 – £19,500 | £17,000 – £22,000 | £21,500 – £28,000 |
| 2 m × 5.5 m 11 m² | £21,000 – £25,500 | £24,000 – £30,500 | £30,000 – £38,500 |
| 2.2 m × 7 m 15 m² | £28,500 – £34,500 | £32,500 – £41,000 | £40,500 – £52,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Our process, step by step
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
We visit your Durham home, measure up, talk through what you want and check the planning position.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Common questions in Durham
Do I need building regulations approval in Durham?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Do you cover all of Durham?
Yes. We cover Durham and the surrounding parts of County Durham. Site visits are free and there is no obligation.
Will my neighbours in Durham be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
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 £1,910 to £3,460 per m² including VAT, so a typical 2 m × 5.5 m infill lands around £24,000 to £30,500 at standard spec in Durham, more in London.
Book a free site visit in Durham
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.