Glass box extensions in Cheltenham
If you live in Cheltenham and want more space without moving, a glass extension is one of the most practical ways to get it. We handle the drawings, approvals and the build.
- Guide price in CheltenhamFrom £30,500 inc VAT
- PlanningSame limits as single-storey rear; glazing checked for building regs
- Build time10–16 weeks on site
- Postcode districtsGL3, GL50, GL51, GL52, GL53
Planning and approvals in Cheltenham
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.
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.
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 Cheltenham
We cover Cheltenham and the postcode districts GL3, GL50, GL51, GL52, GL53. We also work in nearby Tewkesbury (7 miles), Gloucester (7 miles), Stroud (12 miles), Cirencester (13 miles).
South West homes range from terraced streets in the cities to stone cottages and bungalows in the countryside, and conservation areas are common in historic centres.
Is a glass extension right for your house?
- Garden-facing dining rooms
- Small infill spaces and side returns
- Period and listed-style houses where a light touch is wanted
What should I budget for a glass extension in Cheltenham?
These guide figures apply our South West England adjustment (×1.02) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Cheltenham: £3,060 to £5,920 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2 m × 4 m 8 m² | £30,500 – £37,000 | £30,500 – £38,500 | £35,000 – £47,500 |
| 3 m × 4 m 12 m² | £36,500 – £44,500 | £42,500 – £54,000 | £52,500 – £71,000 |
| 3 m × 6 m 18 m² | £55,000 – £66,500 | £64,000 – £81,000 | £78,500 – £106,500 |
Try the guide-price tool to see a range for your own size and finish.
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
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
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
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 Cheltenham
Do I need building regulations approval in Cheltenham?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Cheltenham, 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 you cover all of Cheltenham?
Yes. We cover Cheltenham and the surrounding parts of Gloucestershire. Site visits are free and there is no obligation.
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.
How much does a glass extension cost?
Our guide range is about £3,060 to £5,920 per m² including VAT, because structural glass is made to order. A 12 m² standard-spec glass extension is typically £42,500 to £54,000 in Cheltenham.
Book a free site visit in Cheltenham
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.