Two-storey wraparound extensions in Islington

The basics for Islington at a glance.

Postcode districts: EC1V and N1
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: Barnsbury (0.7 miles), Canonbury (0.7 miles), King's Cross (0.9 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.

We cover postcode districts EC1V and N1 in and around Islington, along with neighbouring Barnsbury, Canonbury and King's Cross.

What it costs in Islington

Guide prices for two-storey wraparound extensions in London are around £2,580–£3,540 per m² of new floor space, including VAT. For 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), that's roughly £144,500–£198,000. Professional fees for drawings and the structural engineer are listed separately on our prices page.

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 Islington

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 Islington homes

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.

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

Measure and listen
A visit to Islington to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.
Choose the approval route
Some designs fit permitted development, most need a householder application. We decide which applies in England before drawing in detail.
Fixed price in writing
With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.
On site
One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.

Questions about two-storey wraparound extensions in Islington

Who handles building regulations for a project in Islington?

We handle it as part of the project. What's needed in England: building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

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 Islington?

Our guide for London, which covers Islington, 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.

Can I stay at home during a wraparound extension?

Many people do, but a wraparound affects two sides of the house and usually the kitchen, so there will be weeks without a full kitchen. We plan a temporary kitchen, keep a route through the house and seal off the work area. For some families, moving out while the rear wall is opened up is easier.

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 Islington

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

Send us your postcode and a few details. We'll get back to you to arrange a visit and talk through your options.