First-floor extensions in Washwood Heath

Washwood Heath: the key facts for this kind of project.

Postcode districts: B8, B9, B23 and B24
County / area: West Midlands, England
Price region: West Midlands
Guide price: £25,000–£36,500 (£1,800–£2,600 per m²)
Approval route: It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission.
Nearest towns: Castle Vale (1.8 miles), Aston (2.4 miles), Birmingham (3.4 miles)
Distance to Birmingham: about 3.4 miles
First visit: Free, no obligation

About a first-floor extension

A first-floor extension suits you if your house already has a single-storey extension and you need more space upstairs. You get a structural check of the existing walls and foundations, a design that ties the new floor into the house, the approvals your nation needs, building regulations approval and the build, managed by us and carried out by vetted teams working under S&K.

Washwood Heath sits about 3.4 miles from Birmingham. Closer to home, Castle Vale is 1.8 miles away and Aston 2.4 miles.

What it costs in Washwood Heath

Our guide for the West Midlands is £1,800–£2,600 per m² including VAT. On a project with 4 m × 3.5 m of new first-floor space (14 m²), that puts a first-floor extension in Washwood Heath at roughly £25,000–£36,500. Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.

Spec	Per m²	4 m × 3.5 m of new first-floor space (14 m²)
Essential	£1,660–£2,390 per m²	£23,000–£33,500
Standard	£1,800–£2,600 per m²	£25,000–£36,500
Premium	£2,160–£3,120 per m²	£30,000–£43,500

Planning and building regulations in Washwood Heath

In England, adding a first floor turns a single-storey extension into one of more than one storey. To be permitted development, the extension as a whole must go no more than 3 m beyond the rear wall of the original house and stay at least 7 m from the rear boundary, with matching materials and roof pitch. Over a side extension it always needs planning permission, costing £548 (or £575 for applications made from 8 December 2026).

Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.

Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.

Design points for Washwood Heath homes

Can the existing structure take it?

Many single-storey extensions were built with foundations, walls and lintels sized for one storey. We find out what is there with trial holes and, where available, the original building control drawings. The engineer then decides whether to reuse, strengthen or rebuild parts of the structure.

Matching the roofline

A first-floor extension often changes how the back or side of the house looks more than the original single storey did. Matching the main roof pitch and materials, and keeping the ridge below the main ridge, usually gives the best result and is expected for permitted development in England.

How we'd run your project

Measure and listen
A visit to Washwood Heath to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Washwood Heath.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
On site
One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.

Questions about first-floor extensions in Washwood Heath

How long does a first-floor extension take?

Allow 4 to 8 weeks for survey and design, then the approval period (councils should decide householder applications within 8 weeks of validation), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.

Which postcodes do you cover around Washwood Heath?

We cover Washwood Heath (B8, B9, B23 and B24) and nearby places including Castle Vale, Aston and Birmingham, plus the rest of the West Midlands. The first site visit is free.

How much does a first-floor extension cost in Washwood Heath?

Our guide for the West Midlands, which covers Washwood Heath, is £1,800–£2,600 per m² including VAT. A typical project with 4 m × 3.5 m of new first-floor space (14 m²) comes to about £25,000–£36,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

What happens to the room below while the first floor is built?

The old roof is removed, so the room below is exposed for a short period. We fit temporary weather protection, plan the work so the roof comes off only when the new structure is ready, and agree with you which rooms will be out of use and for roughly how long.

Can I build on top of my existing single-storey extension?

Often yes, but only after the structure has been checked. Foundations, walls and lintels built for one storey may not carry two. We dig trial holes, look for the original building control approval and ask the structural engineer to confirm what can stay, what needs strengthening and what must be rebuilt.

Nearby

We also cover places near Washwood Heath, including:

Other extensions in Washwood Heath

All two-storey extension services in Washwood Heath · First-floor extensions across the West Midlands

The quickest next step is a visit. We'll look at your house in Washwood Heath and give you an honest view of the options.