Glass box extensions in Birmingham: design, approvals and build
Birmingham homeowners can use us for the whole glass extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in BirminghamFrom £29,000 inc VAT
- PlanningSame limits as single-storey rear; glazing checked for building regs
- Build time10–16 weeks on site
- Postcode districtsB1, B2, B3, B4, B5

Glass extension prices in Birmingham
These guide figures apply our West Midlands adjustment (×0.97) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Birmingham: £2,910 to £5,630 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2 m × 4 m 8 m² | £29,000 – £35,000 | £29,000 – £37,000 | £33,000 – £45,500 |
| 3 m × 4 m 12 m² | £34,500 – £42,000 | £40,500 – £51,500 | £50,000 – £68,000 |
| 3 m × 6 m 18 m² | £52,000 – £63,000 | £61,000 – £77,000 | £75,000 – £101,500 |
Try the guide-price tool to see a range for your own size and finish.
What is included
- Design with specialist glazing input
- Whole-house energy calculations where needed
- Steel or glass beams and slim-frame glazing
- Planning drawings that show the glass detail
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 and approvals in Birmingham
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 Birmingham address depends on its history and any designations, which is why we check it at the first visit.
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.
Applications are decided by the local planning authority (your district, borough or unitary council).
Working in Birmingham
Postcode districts we cover around Birmingham include B1, B2, B3, B4, B5, B19. We also work in nearby Smethwick (3 miles), West Bromwich (5 miles), Shirley (6 miles), Halesowen (7 miles).
Just over the Worcestershire border, Bromsgrove is about 12 miles away. The West Midlands has a large stock of 1930s and post-war semi-detached houses, which are well suited to rear, side and over-garage extensions, plus Victorian terraces in the older inner areas.
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
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Common questions in Birmingham
Do you cover all of Birmingham?
Yes. We cover Birmingham and the surrounding parts of West Midlands. Site visits are free and there is no obligation.
Do I need building regulations approval in Birmingham?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Will my neighbours in Birmingham 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.
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 £2,910 to £5,630 per m² including VAT, because structural glass is made to order. A 12 m² standard-spec glass extension is typically £40,500 to £51,500 in Birmingham.
Book a free site visit in Birmingham
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.