Glass box extensions across Sutton
A glass extension in Sutton starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in SuttonFrom £39,000 inc VAT
- PlanningSame limits as single-storey rear; glazing checked for building regs
- Build time10–16 weeks on site
- Postcode districtsKT4, SM1, SM2, SM3, SM5
Planning and approvals in Sutton
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.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Extensions in and around Sutton
Site visits are available across Sutton (KT4, SM1, SM2, SM3, SM5, SM6). Neighbouring towns we cover include Carshalton (2 miles), Wallington (2 miles), Worcester Park (3 miles), Coulsdon (3 miles).
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.
Guide prices for Sutton
These guide figures apply our London adjustment (×1.3) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Sutton: £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.
When a glass extension makes sense
- Period and listed-style houses where a light touch is wanted
- Small infill spaces and side returns
- 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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Your questions about a glass extension in Sutton
How long does a glass extension take to build in Sutton?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
Do I need building regulations approval in Sutton?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Do you cover all of Sutton?
Yes. We cover Sutton 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 Sutton.
Book a free site visit in Sutton
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.