Glass box extensions in Winchester
From the first sketch to final sign-off, we plan and build glass extensions in Winchester and the surrounding Hampshire area.
- Guide price in WinchesterFrom £33,500 inc VAT
- PlanningSame limits as single-storey rear; glazing checked for building regs
- Build time10–16 weeks on site
- Postcode districtsSO21, SO22, SO23
Local to Winchester
We cover Winchester and the postcode districts SO21, SO22, SO23. The same team covers Eastleigh (7 miles), Southampton (12 miles), Totton (13 miles), Andover (13 miles), all within easy reach.
In the South East, plenty of houses have already been extended once, which makes checking the remaining permitted development allowance an important early step.
How much does a glass extension cost in Winchester?
Prices below are for Winchester, 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 Winchester: £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.
Included in a typical project
- Solar-control and low-energy glass specification
- Planning drawings that show the glass detail
- Whole-house energy calculations where needed
- Design with specialist glazing input
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.
Planning rules that apply in Winchester
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 Winchester 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.
Applications are decided by the local planning authority (your district, borough or unitary council).
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
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
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions people ask about glass extensions
Who do I contract with for a glass extension in Winchester?
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.
Do you cover all of Winchester?
Yes. We cover Winchester and the surrounding parts of Hampshire. Site visits are free and there is no obligation.
Do I need building regulations approval in Winchester?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
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 £3,360 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 Winchester.
Book a free site visit in Winchester
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.