Part single, part two-storey extensions in Washwood Heath

Before you start in Washwood Heath, here's what applies.

Postcode districts: B8, B9, B23 and B24
County / area: West Midlands, England
Price region: West Midlands
Guide price: £72,000–£99,000 (£2,000–£2,750 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 part single, part two-storey extension

A part single, part two-storey extension is an extension where the ground floor is wider or deeper than the floor above, so only part of it rises to two storeys. It usually gives a large kitchen or living area with roof lights below and one bedroom or bathroom above. It is often a good way to add space while limiting the effect on neighbours.

We cover Washwood Heath (B8, B9, B23 and B24) and the places around it, including Castle Vale (1.8 miles), Aston (2.4 miles) and Birmingham.

What it costs in Washwood Heath

For budgeting in Washwood Heath, allow around £72,000–£99,000 for a part single, part two-storey extension with a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total). That's based on £2,000–£2,750 per m² including VAT for the West Midlands. We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.

Spec	Per m²	A 6 m × 4 m ground floor and a first floor over half of it (36 m² in total)
Essential	£1,840–£2,530 per m²	£66,000–£91,000
Standard	£2,000–£2,750 per m²	£72,000–£99,000
Premium	£2,400–£3,300 per m²	£86,500–£119,000

Planning and building regulations in Washwood Heath

In England, the extension can only be permitted development if it goes no more than 3 m beyond the original rear wall and stays at least 7 m from the rear boundary, with matching materials and roof pitch. We check the whole design against the rules, including the 50% garden coverage limit. If any part fails, or extends beyond a side wall on two floors, you need 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

Where to put the two-storey part

The two-storey section usually works best away from the closest neighbour, with the single-storey part on that boundary side. We test a few positions against neighbours' windows, the upstairs layout and the roof shape before choosing the one to take forward.

Light into the kitchen

The single-storey part is the place for roof lights or a lantern, which bring daylight deep into the plan. In England, glazing is normally limited to 25% of the new floor area plus any windows removed, unless calculations show the house still performs, so we plan the balance early.

How we'd run your project

Free site visit
We visit your home in Washwood Heath, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Choose the approval route
Some designs fit permitted development, most need a householder application. We decide which applies in England before drawing in detail.
Price it properly
Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Questions about part single, part two-storey extensions in Washwood Heath

How long does a part single, part two-storey 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.

How much does a part single, part two-storey extension cost in Washwood Heath?

Our guide for the West Midlands, which covers Washwood Heath, is £2,000–£2,750 per m² including VAT. A typical project with a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total) comes to about £72,000–£99,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

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.

Which side should the two-storey part go on?

Usually the side furthest from the nearest neighbour's windows, so the single-storey part sits nearest them and keeps their light. Other factors are where the stairs land upstairs, which room needs the extra space and where drains run. We sketch options at the design stage and explain which is most likely to be approved.

Can I add roof lights to the single-storey part?

Yes. Roof lights or a lantern over the single-storey part are one of the main reasons to choose this design, as they light the middle of a deep kitchen. In England they count towards the Part L glazing allowance, normally 25% of the new floor area plus windows removed, so we balance them with the rear doors.

Nearby

Close to Washwood Heath? We work across the area, including:

Other extensions in Washwood Heath

All two-storey extension services in Washwood Heath · Part single, part two-storey extensions across the West Midlands

Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Washwood Heath.