Double-storey extensions in Smethwick: design, approvals and build
From the first sketch to final sign-off, we plan and build double-storey extensions in Smethwick and the surrounding West Midlands area.
- Guide price in SmethwickFrom £36,500 inc VAT
- PlanningUsually a householder application
- Build time16–24 weeks on site
- Postcode districtsB16, B18, B21, B66, B67
What should I budget for a double-storey extension in Smethwick?
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 Smethwick: £1,500 to £2,910 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m, two floors 24 m² | £36,500 – £44,000 | £41,500 – £55,000 | £53,500 – £70,000 |
| 4 m × 4 m, two floors 32 m² | £48,000 – £57,500 | £55,500 – £73,000 | £71,000 – £93,500 |
| 4 m × 6 m, two floors 48 m² | £72,000 – £86,500 | £83,500 – £109,500 | £107,000 – £140,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Local to Smethwick
Across B16, B18, B21, B66, B67, B68, we can visit, measure and advise. Nearby, we also take on projects in West Bromwich (2 miles), Birmingham (3 miles), Halesowen (5 miles), Wednesbury (5 miles).
Just over the Worcestershire border, Bromsgrove is about 12 miles away. Across the West Midlands, brick-built semis with long gardens are common, so single-storey and two-storey rear extensions are popular choices.
Do I need planning permission in Smethwick?
In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
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).
Is a double-storey extension right for your house?
- Growing families who need a bedroom as well as a bigger kitchen
- Houses with enough distance to the rear or side boundary
- Homeowners who would otherwise consider moving
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
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
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions people ask about double-storey extensions
Do you cover all of Smethwick?
Yes. We cover Smethwick and the surrounding parts of West Midlands. Site visits are free and there is no obligation.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Smethwick, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Will my neighbours in Smethwick 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.
Do I need a Party Wall Agreement?
If you are in England or Wales and the work involves a shared wall or digging foundations close to a neighbour, the Party Wall etc. Act 1996 applies and notices must be served before work starts. We tell you which notices are needed.
Is a two-storey extension cheaper per square metre?
Usually. Our guide range is about £1,500 to £2,910 per m² of new floor area including VAT, compared with £1,700 to £3,300 per m² for single-storey work, because the foundations and roof are shared across two floors.
Book a free site visit in Smethwick
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.