Double-storey extensions in Kings Heath

Planning your two-storey extension in Kings Heath

Most two-storey extensions in Kings Heath need a planning application to Birmingham City Council. A two-storey rear extension can sometimes be permitted development, but only if it is no more than 3 m deep and at least 7 m from the rear boundary, among other conditions. Building Regulations approval is needed either way.

Councils often expect a side extension's first floor to be set back from the front wall, with its roof below the main ridge.
An upstairs en-suite is simplest when the new bathroom sits close to the existing soil stack.
The householder planning fee in England is £548 from April 2026, paid to Birmingham City Council when you apply.

Postcode district: B14
Planning and building control: Birmingham City Council
From our West Bromwich base: 8 miles

Which option fits your home?

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.

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.

How much should you budget in Kings Heath?

For a home in Kings Heath, 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.

Questions about double-storey extensions in Kings Heath

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 Kings Heath?

Yes. Kings Heath (B14) 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.

Does Birmingham City Council need to approve my two-storey extension?

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.

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More services in Kings Heath

Ask for a free survey in Kings Heath and we'll tell you what's likely to get planning before you pay for drawings.