Two-storey wraparound extensions in Thornton Heath

What we'd confirm first for a project in Thornton Heath.

Postcode districts: CR7
County / area: Greater London, England
Price region: London
Guide price: £144,500–£198,000 (£2,580–£3,540 per m²)
Approval route: Planning permission is needed: the side part takes it outside permitted development in England.
Nearest towns: South Norwood (1 mile), Croydon (1.1 miles), Upper Norwood (1.2 miles)
First visit: Free, no obligation

About a two-storey wraparound extension

A two-storey wraparound extension is an L-shaped addition that extends both the side and the rear of your house, on two floors. It gives one of the largest gains in floor space of any extension, typically a big open-plan kitchen and living area below and two or more bedrooms or bathrooms above. In England it needs planning permission, because the side part is more than one storey.

Around Thornton Heath we also work in South Norwood, Croydon and Upper Norwood, and across the rest of Greater London. Postcode district in and near Thornton Heath: CR7.

What it costs in Thornton Heath

Most of the cost of a two-storey wraparound extension is set by its size and specification. For Thornton Heath and the rest of London, our guide is £2,580–£3,540 per m² including VAT, so about £144,500–£198,000 for an L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space). 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	£2,370–£3,260 per m²	£133,000–£182,500
Standard	£2,580–£3,540 per m²	£144,500–£198,000
Premium	£3,100–£4,250 per m²	£173,500–£238,000

Planning and building regulations in Thornton Heath

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 Thornton Heath homes

Phasing the build

A wraparound touches two sides of the house at once, so the kitchen and often the rear rooms are out of use for part of the build. We plan the sequence so you keep a working kitchen and bathroom for as long as possible, or advise when moving out briefly makes sense.

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.

How we'd run your project

Free site visit
We visit your home in Thornton Heath, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Structure and building control
A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.
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 Thornton Heath

Which postcodes do you cover around Thornton Heath?

We cover Thornton Heath (CR7) and nearby places including South Norwood, Croydon and Upper Norwood, plus the rest of Greater London. The first site visit is free.

How much does a two-storey wraparound extension cost in Thornton Heath?

Our guide for London, which covers Thornton Heath, is £2,580–£3,540 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 £144,500–£198,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

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 floor space does a wraparound extension add?

It depends on the width of the side plot and the depth at the rear. Our guide prices are based on a typical wraparound with an L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space). Yours may be larger or smaller, and the measured survey shows what your plot can take.

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.

Nearby

Nearby towns we cover for two-storey wraparound extensions:

Other extensions in Thornton Heath

All two-storey extension services in Thornton Heath · Two-storey wraparound extensions across Greater London

Book a free site visit in Thornton Heath and we'll tell you what's possible, what approvals you need and what the design stage would cost.