Glass box extensions in Bishop's Stortford: design, approvals and build
From the first sketch to final sign-off, we plan and build glass extensions in Bishop's Stortford and the surrounding Hertfordshire area.
- Guide price in Bishop's StortfordFrom £31,500 inc VAT
- PlanningSame limits as single-storey rear; glazing checked for building regs
- Build time10–16 weeks on site
- Postcode districtsCM23

What should I budget for a glass extension in Bishop's Stortford?
Labour and material costs vary across the UK, so for Bishop's Stortford we use our East of England factor (×1.06). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Bishop's Stortford: £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.
When a glass extension makes sense
- Garden-facing dining rooms
- Small infill spaces and side returns
- Period and listed-style houses where a light touch is wanted
Covering Bishop's Stortford
Site visits are available across Bishop's Stortford (CM23). We also work in nearby Hoddesdon (10 miles), Hertford (11 miles), Cheshunt (14 miles), Stevenage (16 miles).
Harlow, in Essex, is roughly 7 miles from Bishop's Stortford and also on our list. The East of England mixes market-town terraces, inter-war semis and modern estates. Clay soils are common in parts of the region, which can affect foundation design.
Do I need planning permission in Bishop's Stortford?
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 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).
Our process, step by step
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions in Bishop's Stortford
Who do I contract with for a glass extension in Bishop's Stortford?
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.
Will my neighbours in Bishop's Stortford 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 Bishop's Stortford, 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 Bishop's Stortford.
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 Bishop's Stortford
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.