Glass box extensions for homes in Dunstable
We design and build glass extensions for houses in Dunstable, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in DunstableFrom £31,500 inc VAT
- PlanningSame limits as single-storey rear; glazing checked for building regs
- Build time10–16 weeks on site
- Postcode districtsLU4, LU5, LU6
How much does a glass extension cost in Dunstable?
Prices below are for Dunstable, using the East of England factor of ×1.06. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Dunstable: £3,180 to £6,150 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2 m × 4 m 8 m² | £31,500 – £38,500 | £31,500 – £40,000 | £36,000 – £49,500 |
| 3 m × 4 m 12 m² | £38,000 – £46,000 | £44,500 – £56,000 | £54,500 – £74,000 |
| 3 m × 6 m 18 m² | £57,000 – £69,000 | £66,500 – £84,000 | £82,000 – £111,000 |
Try the guide-price tool to see a range for your own size and finish.
Will the council need to approve it?
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.
The planning position for a specific Dunstable address depends on its history and any designations, which is why we check it at the first visit.
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).
What is included
- Design with specialist glazing input
- Solar-control and low-energy glass specification
- Whole-house energy calculations where needed
- Drainage details for frameless roofs
- Steel or glass beams and slim-frame glazing
Solar gain is the risk. We specify solar-control glass, plan for opening vents or sliding panels, and avoid fully glazed roofs on south-facing extensions unless shading is included.
Extensions in and around Dunstable
Site visits are available across Dunstable (LU4, LU5, LU6). We also work in nearby Luton (5 miles), Leighton Buzzard (6 miles), Ampthill (10 miles), Kempston (16 miles).
Just over the Hertfordshire border, Harpenden is about 9 miles away. Across the East of England many houses sit on generous plots, and single-storey and wraparound extensions are a natural fit.
How the project works
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
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Glass extension questions answered
How long does a glass extension take to build in Dunstable?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
Will my neighbours in Dunstable 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 see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Dunstable, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
How much does a glass extension cost?
Our guide range is about £3,180 to £6,150 per m² including VAT, because structural glass is made to order. A 12 m² standard-spec glass extension is typically £44,500 to £56,000 in Dunstable.
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 Dunstable
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.