Two-storey wraparound extensions in Knowle

What we'd confirm first for a project in Knowle.

Postcode districts: B93
County / area: West Midlands, England
Price region: West Midlands
Guide price: £120,500–£165,000 (£2,150–£2,950 per m²)
Approval route: Planning permission is needed: the side part takes it outside permitted development in England.
Nearest towns: Solihull (2.9 miles), Shirley (West Midlands) (4.1 miles), Acocks Green (5.8 miles)
Distance to Birmingham: about 9.8 miles
First visit: Free, no obligation

About a two-storey wraparound extension

A two-storey wraparound extension suits a house with space both beside it and behind it, where you want to transform the layout rather than add a single room. You get one design for the whole L-shape, the planning application, structural design for the corner and the openings into the house, building regulations approval and the build, managed by us and carried out by vetted teams working under S&K.

Around Knowle we also work in Solihull, Shirley (West Midlands) and Acocks Green, and across the rest of the West Midlands. Postcode district in and near Knowle: B93.

What it costs in Knowle

In the West Midlands, which includes Knowle, we'd expect a two-storey wraparound extension to cost around £120,500–£165,000 for an L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space), or £2,150–£2,950 per m² including VAT. Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.

Spec	Per m²	An L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space)
Essential	£1,980–£2,710 per m²	£111,000–£152,000
Standard	£2,150–£2,950 per m²	£120,500–£165,000
Premium	£2,580–£3,540 per m²	£144,500–£198,000

Planning and building regulations in Knowle

In England, a two-storey wraparound extension needs householder planning permission, because any extension beyond a side wall must be single storey to be permitted development. The application costs £548 (or £575 for applications made from 8 December 2026). Councils weigh the side part against the street scene and the rear part against neighbours' light and outlook, and should decide within 8 weeks of validation.

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 Knowle homes

Daylight to the middle

A deep L-shaped plan can leave the middle of the ground floor dark, because the old rear rooms are now enclosed. We use wide rear openings, a well-placed stair and, where part of the extension is single storey, roof lights, while keeping total glazing within the Part L allowance.

Two roofs that meet

A wraparound needs the side roof and rear roof to join cleanly, often with a valley or hip where they meet. Getting pitches and ridge heights right keeps rainwater moving and avoids a bulky mass at the back corner, which neighbours and planners notice.

How we'd run your project

Start at your house
We come to your home in Knowle, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
Build and sign-off
Vetted teams working under S&K build the extension, and we arrange the building control completion certificate at the end.

Questions about two-storey wraparound extensions in Knowle

How long does a two-storey wraparound 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 two-storey wraparound extension cost in Knowle?

Our guide for the West Midlands, which covers Knowle, is £2,150–£2,950 per m² including VAT. A typical project with an L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space) comes to about £120,500–£165,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

Do I need planning permission for a two-storey wraparound extension in Knowle?

Knowle is in England, so England planning rules apply. Planning permission is needed: the side part takes it outside permitted development in England. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

Does a wraparound extension need steel?

Almost always. Opening the corner of the house and the old rear wall to make one open-plan space means steel beams, and often a steel post or frame at the outside corner. The structural engineer sizes these, and the steel is ordered once the design is fixed, which is one reason a wraparound needs careful sequencing.

Can a wraparound extension be part single, part two-storey?

Yes. Many wraparounds keep the rear part single storey with roof lights over the kitchen and put the two-storey part to the side. This can reduce the effect on neighbours and the cost. We set out both options at the design stage, so you can compare floor space against price before choosing.

Nearby

The same service in neighbouring towns:

Other extensions in Knowle

All two-storey extension services in Knowle · Two-storey wraparound extensions across the West Midlands

Tell us about your house in Knowle and we'll call you back to arrange a free, no-obligation visit.