Glass box extensions for homes in Thame
Our design and build teams take on glass extensions in Thame, from the first measured survey through planning and building control to the finished room.
- Guide price in ThameFrom £33,500 inc VAT
- PlanningSame limits as single-storey rear; glazing checked for building regs
- Build time10–16 weeks on site
- Postcode districtsOX9

Glass extension prices in Thame
Prices below are for Thame, using the South East England factor of ×1.12. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Thame: £3,360 to £6,500 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2 m × 4 m 8 m² | £33,500 – £40,500 | £33,500 – £42,500 | £38,500 – £52,000 |
| 3 m × 4 m 12 m² | £40,000 – £48,500 | £47,000 – £59,500 | £57,500 – £78,000 |
| 3 m × 6 m 18 m² | £60,000 – £73,000 | £70,500 – £89,000 | £86,500 – £117,000 |
Try the guide-price tool to see a range for your own size and finish.
Do I need planning permission in Thame?
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.
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 Thame
We cover Thame and the postcode districts OX9. Nearby, we also take on projects in Oxford (12 miles), Bicester (13 miles), Henley-on-Thames (14 miles), Abingdon (14 miles).
For homes towards Buckinghamshire, Aylesbury is around 9 miles away. Homes across the South East range from Victorian terraces in the older town centres to large detached houses on the edges, so the right extension type varies street by street.
Who a glass extension suits
- Small infill spaces and side returns
- Period and listed-style houses where a light touch is wanted
- Garden-facing dining rooms
What happens next
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 draw the design, agree it with you and handle planning or permitted development checks and building regulations.
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
How long does a glass extension take to build in Thame?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Thame, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Who do I contract with for a glass extension in Thame?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
How much does a glass extension cost?
Our guide range is about £3,360 to £6,500 per m² including VAT, because structural glass is made to order. A 12 m² standard-spec glass extension is typically £47,000 to £59,500 in Thame.
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 Thame
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.