Glass box extensions across Blyth
Our design and build teams take on glass extensions in Blyth, from the first measured survey through planning and building control to the finished room.
- Guide price in BlythFrom £27,000 inc VAT
- PlanningSame limits as single-storey rear; glazing checked for building regs
- Build time10–16 weeks on site
- Postcode districtsNE24

Do I need planning permission in Blyth?
In England a glazed or orangery-style extension follows the same size limits as any single-storey rear extension: 3 m or 4 m without an application, or up to 6 m and 8 m through prior approval. Building regulations limit glazing to about a quarter of the new floor area plus the openings it replaces, unless whole-house calculations show the design still performs.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
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.
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).
What should I budget for a glass extension in Blyth?
Prices below are for Blyth, using the North East England factor of ×0.91. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Blyth: £2,730 to £5,280 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2 m × 4 m 8 m² | £27,000 – £33,000 | £27,000 – £34,500 | £31,000 – £42,500 |
| 3 m × 4 m 12 m² | £32,500 – £39,500 | £38,000 – £48,500 | £46,500 – £63,500 |
| 3 m × 6 m 18 m² | £49,000 – £59,000 | £57,000 – £72,500 | £70,000 – £95,500 |
Try the guide-price tool to see a range for your own size and finish.
Local to Blyth
We cover Blyth and the postcode districts NE24. Neighbouring towns we cover include Bedlington (3 miles), Ashington (4 miles), Cramlington (4 miles), Morpeth (8 miles).
Across the North East, houses often have rear yards or modest gardens, so compact, well-lit single-storey extensions make the biggest difference.
What we take care of
- Whole-house energy calculations where needed
- Drainage details for frameless roofs
- Design with specialist glazing input
- Solar-control and low-energy glass specification
- Steel or glass beams and slim-frame glazing
- Planning drawings that show the glass detail
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
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
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Glass extension questions answered
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Blyth, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
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.
How long does a glass extension take to build in Blyth?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
How much does a glass extension cost?
Our guide range is about £2,730 to £5,280 per m² including VAT, because structural glass is made to order. A 12 m² standard-spec glass extension is typically £38,000 to £48,500 in Blyth.
Are glass extensions cold in winter?
Modern double or triple glazing with warm-edge spacers and underfloor heating keeps them comfortable. They are not as warm as a solid room, and we explain the trade-off honestly.
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.