Glass box extensions in Highbury: design, approvals and build
Our design and build teams take on glass extensions in Highbury, from the first measured survey through planning and building control to the finished room.
- Guide price in HighburyFrom £39,000 inc VAT
- PlanningSame limits as single-storey rear; glazing checked for building regs
- Build time10–16 weeks on site
- Postcode districtsN1C, N1, N4, N5, N7

Glass extension prices in Highbury
Labour and material costs vary across the UK, so for Highbury we use our London factor (×1.3). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Highbury: £3,900 to £7,540 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2 m × 4 m 8 m² | £39,000 – £47,000 | £39,000 – £49,500 | £44,500 – £60,500 |
| 3 m × 4 m 12 m² | £46,500 – £56,500 | £54,500 – £69,000 | £67,000 – £90,500 |
| 3 m × 6 m 18 m² | £70,000 – £84,500 | £81,500 – £103,000 | £100,500 – £136,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Working in Highbury
Our survey diary covers Highbury, including N1C, N1, N4, N5, N7, N16. Nearby, we also take on projects in Holloway (1 mile), Stamford Hill (2 miles), Camden Town (2 miles), Chalk Farm (2 miles).
For homes towards Essex, Waltham Abbey is around 10 miles away. In London, space is at a premium and gardens are often short, so side returns, wraparounds and carefully planned rear extensions tend to make the most of every metre.
Is a glass extension right for your house?
- Small infill spaces and side returns
- Period and listed-style houses where a light touch is wanted
- Garden-facing dining rooms
Planning and approvals in Highbury
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 Highbury 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).
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
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
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Common questions in Highbury
Do I need building regulations approval in Highbury?
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 Highbury, 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 Highbury?
Yes. We cover Highbury and the surrounding parts of Greater London. 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 £3,900 to £7,540 per m² including VAT, because structural glass is made to order. A 12 m² standard-spec glass extension is typically £54,500 to £69,000 in Highbury.
Book a free site visit in Highbury
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.