Double-storey extensions in Selly Oak

Planning your two-storey extension in Selly Oak

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

Under permitted development, a rear extension of more than one storey can project no more than 3 metres and must be at least 7 metres from the rear boundary.
New first-floor bedrooms normally need an escape window with at least 0.33 m² of clear openable area.
Scaffolding is usually up for most of the build, so think about access along the side of the house early.

Postcode district: B29
Planning and building control: Birmingham City Council
From our West Bromwich base: 6 miles

Choices to weigh up in Selly Oak

Combined side and rear

An L-shaped two-storey build wrapping the side and back of the house gives the biggest gain, sometimes two extra bedrooms. It's a substantial project with more steel and a complex roof junction, and it will need a householder planning application. Expect a longer programme and a careful plan for keeping the house secure while the roofs are joined.

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.

How much should you budget in Selly Oak?

For a home in Selly Oak, our guide range is £52,000–£135,000 depending on size and specification. A two-storey side extension on a three-bed semi, about 32 m² over two floors: usually £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. A free survey turns this guide into a fixed, itemised price.

Your questions answered

Is a double-storey extension better value than a single-storey one?

Per square metre, usually yes. Foundations and roofs are the expensive parts of any extension, and on a two-storey build they serve twice the floor area. You'll pay more in total and planning is less certain, but if you need a bedroom as well as downstairs space, building both together normally costs less than two separate projects years apart.

Do you cover Selly Oak?

Yes. Selly Oak (B29) is about 6 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 Selly Oak?

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.

Double-storey extensions near Selly Oak

Other home improvements in Selly Oak

Let's talk about the space you need; a written, itemised quote for your Selly Oak home costs nothing and commits you to nothing.