Double-storey extensions in Bournville

What should you know before starting in Bournville?

Expect to apply to Birmingham City Council for planning permission for a two-storey extension in Bournville; side extensions over one storey always need it. We prepare the drawings, and the structural work also needs Building Regulations approval.

New first-floor bedrooms normally need an escape window with at least 0.33 m² of clear openable area.
Party wall notices take one or two months to run, so they're best served as soon as planning is granted.
The householder planning fee in England is £548 from April 2026, paid to Birmingham City Council when you apply.

Postcode district: B30
Planning and building control: Birmingham City Council
From our West Bromwich base: 8 miles

Which options suit homes in Bournville?

Mixed-height extension

A two-storey section at the side with a single-storey section running across the back. This keeps the first floor away from neighbours' windows while still giving a wide kitchen-diner below. It's a practical compromise where planners have concerns about a full-depth two-storey rear extension, and it often simplifies the roof.

Two-storey side extension

Built over the side of the house, often where a driveway or old garage sits. It can create a garage, utility or study downstairs with a double bedroom above. Councils often expect the upper floor to be set back from the front and the roof to sit lower than the main ridge, so the design needs care to win approval.

Guide prices for Bournville

Expect to budget between £52,000 and £135,000 depending on size and specification in Bournville. A two-storey side extension on a three-bed semi, about 32 m² over two floors: typically £68,000–£88,000.

Guide prices for double-storey extensions
Option	Guide price	Good to know
Compact two-storey rear (20–28 m² total)	£52,000 – £72,000	Bigger kitchen below, bedroom or bathroom above
Two-storey side or rear (30–40 m² total)	£68,000 – £98,000	The usual size on a three-bed semi
Large or combined side and rear (45 m²+)	£95,000 – £135,000	More steel, a complex roof and a longer programme

Guide ranges include VAT where it applies. We confirm a fixed price for the agreed specification after visiting.

Your questions answered

How long does a double-storey extension take?

Plan on 14–22 weeks on site, depending on size and roof complexity. Before that, allow time for drawings, a planning decision (councils aim to decide householder applications within 8 weeks), Building Regulations drawings and party wall notices. It's worth starting the design well ahead of when you need the space, because the approvals stage can take as long as the build.

Do you cover Bournville?

Yes. Bournville (B30) is about 8 miles from our West Bromwich base and inside the area we cover. Call 0800 088 6248 or send the form on this page to book a free survey.

What paperwork will I have at the end?

You'll get the building control completion certificate, the electrical installation certificate, your planning decision notice and the manufacturers' guarantee documents for windows, doors and roof products, with their terms set out in your quote. Keep these together, as a buyer's solicitor will ask for them when you sell. Ask us for current insurance details with your quote.

Who approves double-storey extensions in Bournville?

Usually both. Most two-storey extensions need a planning application to Birmingham City Council, and the structural work needs Building Regulations approval from its building control team or a registered building control approver.

Nearby places we cover

Other work we do in Bournville

Want a guide figure first? Use our quote tool for your Bournville extension, then book a survey for a fixed price for the agreed specification.