Glass box extensions in Market Harborough
We design and build glass extensions for houses in Market Harborough, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in Market HarboroughFrom £28,500 inc VAT
- PlanningSame limits as single-storey rear; glazing checked for building regs
- Build time10–16 weeks on site
- Postcode districtsLE16

Working in Market Harborough
Our survey diary covers Market Harborough, including LE16. We also work in nearby Corby (10 miles), Kettering (10 miles), Wellingborough (15 miles), Northampton (16 miles).
Homes across the East Midlands often have usable side land or a driveway beside the house, which opens up side and wraparound options.
Included in a typical project
- Solar-control and low-energy glass specification
- Planning drawings that show the glass detail
- Drainage details for frameless roofs
- 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.
What should I budget for a glass extension in Market Harborough?
Prices below are for Market Harborough, using the East Midlands factor of ×0.95. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Market Harborough: £2,850 to £5,510 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2 m × 4 m 8 m² | £28,500 – £34,500 | £28,500 – £36,000 | £32,500 – £44,500 |
| 3 m × 4 m 12 m² | £34,000 – £41,500 | £39,500 – £50,500 | £49,000 – £66,500 |
| 3 m × 6 m 18 m² | £51,000 – £62,000 | £59,500 – £75,500 | £73,500 – £99,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
Planning rules that apply in Market Harborough
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.
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).
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 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
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions in Market Harborough
Do I need building regulations approval in Market Harborough?
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 Market Harborough, 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 Market Harborough?
Yes. We cover Market Harborough and the surrounding parts of Northamptonshire. 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 £2,850 to £5,510 per m² including VAT, because structural glass is made to order. A 12 m² standard-spec glass extension is typically £39,500 to £50,500 in Market Harborough.
Book a free site visit in Market Harborough
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.