Single-storey extensions in Birmingham

Single-storey extensions in Birmingham: approvals and local details

Birmingham City Council is the planning authority for Birmingham. If your plans need permission, apply early: householder applications have an eight-week target for a decision. Building Regulations approval and inspections run alongside the build.

Under permitted development, a rear extension on a semi or terrace can usually project 3 metres from the original back wall, or 6 metres through the prior approval route.
Most of the build happens outside, so the kitchen is usually only out of action for one to three weeks near the end.
Every extension needs Building Regulations approval, even when planning permission isn't required.

Postcode districts: B1, B7, B9, B10, B12, B18
Planning and building control: Birmingham City Council
From our West Bromwich base: About 6 miles to the centre

Which option fits your home?

Side or side-return extension

Uses the strip of land beside the house, often a passage or driveway. Under permitted development a side extension can be up to half the width of the original house and no more than 4 metres high. On a terrace with a narrow side return, it can widen a galley kitchen considerably without eating into the garden.

Flat roof or pitched roof

Flat roofs, usually GRP fibreglass or EPDM rubber, keep the height down near boundaries and suit roof lanterns. Pitched or lean-to roofs with tiles to match the house look more traditional and shed rain faster, but need more height. The choice affects permitted development limits, cost, and how much light reaches the existing rooms.

Guide prices for Birmingham

Expect to budget between £28,000 and £90,000 depending on size and specification in Birmingham. A 4 m × 5 m rear extension on a semi, with roof lights and bifold doors: typically £40,000–£52,000.

Guide prices for single-storey extensions
Option	Guide price	Good to know
Small rear or side extension (10–15 m²)	£28,000 – £40,000	Utility, WC or a modest kitchen extension
Rear kitchen-diner extension (18–25 m²)	£38,000 – £58,000	The glazing spec moves it within the range
Wrap-around or large extension (30 m²+)	£58,000 – £90,000	More steel and roof, and normally a planning application

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

Before you book in Birmingham

Can we live at home during the build?

Yes, most families stay at home throughout. For the first several weeks the work is outside and your house is closed off from it. The disruptive part is the break-through, when the back wall comes out and the kitchen may be out of action for one to three weeks. We agree a plan for a temporary sink and cooking space before that stage starts.

How do I book a survey in Birmingham?

Send the form on this page, use the guide-price tool or call 0800 088 6248 free. We'll ask a few questions about your single-storey extension and arrange a time to visit.

How much does a single-storey extension cost in the West Midlands?

Most single-storey extensions in the West Midlands cost between £28,000 and £90,000, including VAT where it applies. A typical 4 m × 5 m rear kitchen-diner on a semi, with roof lights and bifold doors, usually costs £40,000–£52,000 built to a finish ready for decorating. Kitchen units, flooring and decorating are extra. After the free survey you get a fixed price for the agreed specification.

Will I need permission from the council in Birmingham?

Usually building control, and sometimes planning. Birmingham City Council is the planning authority for Birmingham; Building Regulations approval comes from its building control team or a registered building control approver. We'll tell you which applies after the survey.

Single-storey extensions across Birmingham

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Single-storey extensions near Birmingham

Other home improvements in Birmingham

Get a guide price for your Birmingham extension in a couple of minutes, then a fixed price for the agreed specification after the survey.