Side extensions across Birmingham
Birmingham homeowners can use us for the whole side extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in BirminghamFrom £21,000 inc VAT
- PlanningSingle storey can be permitted development
- Build time10–18 weeks on site
- Postcode districtsB1, B2, B3, B4, B5
Planning and approvals in Birmingham
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a householder planning application.
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.
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 much does a side extension cost 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: £1,700 to £3,300 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2.5 m × 5 m 12 m² | £21,000 – £26,000 | £23,500 – £31,000 | £30,000 – £40,000 |
| 3 m × 6 m 18 m² | £30,500 – £37,000 | £35,500 – £46,500 | £45,000 – £59,500 |
| 3 m × 8 m 24 m² | £40,500 – £49,000 | £47,500 – £62,000 | £60,500 – £79,500 |
For a figure based on your own dimensions, use our guide-price tool.
Local to Birmingham
Site visits are available across Birmingham (B1, B2, B3, B4, B5, B19). The same team covers Smethwick (3 miles), West Bromwich (5 miles), Shirley (6 miles), Halesowen (7 miles), all within easy reach.
Bromsgrove, in Worcestershire, is roughly 12 miles from Birmingham and also on our list. 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.
Included in a typical project
- Survey, design and street-view drawings
- Structure, roof tied into the house
- Planning route checked or application made
- New openings through the side wall
- Windows, doors and finishes to match
- Foundations near boundaries and any drains
From first visit to completion
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
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
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
The build is managed from start to finish, inspected at each stage and signed off on completion.
Your questions about a side extension in Birmingham
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.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Birmingham, 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 long does a side extension take to build in Birmingham?
On site, typically 10 to 18 weeks once approvals are in place. Before that, allow 6–14 weeks design and approvals.
How close to the boundary can I build?
It depends on height. In England, within 2 m of a boundary the eaves must not exceed 3 m under permitted development. Building on the boundary is possible but brings party wall and maintenance access issues we plan for.
How much does a side extension cost?
Our guide range is about £1,700 to £3,300 per m² including VAT, depending on specification, so a standard 18 m² single-storey side extension lands around £35,500 to £46,500 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.