Side return extensions across Blyth
A side return extension in Blyth 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 BlythFrom £16,000 inc VAT
- PlanningOften permitted development; party wall notice usual
- Build time10–14 weeks on site
- Postcode districtsNE24

Working in Blyth
Across NE24, we can visit, measure and advise. Nearby, we also take on projects in Bedlington (3 miles), Ashington (4 miles), Cramlington (4 miles), Morpeth (8 miles).
For homes towards Tyne and Wear, Whitley Bay is around 7 miles away. The North East has many brick terraces, colliery-era housing and post-war semis, with rear extensions and kitchen extensions the most common requests.
Guide prices for Blyth
For Blyth we adjust our national guide rates by ×0.91, the factor we use for North East England. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Blyth: £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.
Is a side return extension right for your house?
- Narrow galley kitchens
- Homes where the garden is too small to lose much depth
- Victorian and Edwardian terraces with a rear outrigger
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.
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.
The planning position for a specific Blyth address depends on its history and any designations, which is why we check it at the first visit.
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.
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).
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
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
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.
Questions people ask about side return extensions
Do you cover all of Blyth?
Yes. We cover Blyth and the surrounding parts of Northumberland. Site visits are free and there is no obligation.
Will my neighbours in Blyth 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.
Do I need building regulations approval in Blyth?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Will the kitchen be darker?
Not if the roof is designed well. A glazed roof or a line of rooflights along the boundary usually makes the room brighter than before.
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 Blyth, more in London.
Book a free site visit in Blyth
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.