Two-storey wraparound extensions in Knotty Ash

Useful details for planning a two-storey wraparound extension in Knotty Ash.

Postcode districts: L14 and L28
County / area: Merseyside, England
Price region: North West England
Guide price: £114,500–£157,000 (£2,040–£2,800 per m²)
Approval route: Planning permission is needed: the side part takes it outside permitted development in England.
Nearest towns: Old Swan (0.5 miles), West Derby (1.3 miles), Childwall (1.3 miles)
Distance to Liverpool: about 3.4 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.

Knotty Ash sits about 3.4 miles from Liverpool. Closer to home, Old Swan is 0.5 miles away and West Derby 1.3 miles.

What it costs in Knotty Ash

A guide price for Knotty Ash: around £114,500–£157,000 for an L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space). That works out at £2,040–£2,800 per m² of new floor space, including VAT at 20%. These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.

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	£1,880–£2,580 per m²	£105,000–£144,500
Standard	£2,040–£2,800 per m²	£114,500–£157,000
Premium	£2,450–£3,360 per m²	£137,500–£188,500

Planning and building regulations in Knotty Ash

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 Knotty Ash 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.

The corner post

At the outside corner of the L, there is no existing wall to carry the floor above. Opening the ground floor fully usually means a steel frame or a corner post, and the engineer's design sets how slim it can be. We decide early whether you want a clear corner or a visible post.

How we'd run your project

Free site visit
We visit your home in Knotty Ash, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Get it approved
Once you're happy with the design we submit it to the council for Knotty Ash and deal with any questions from the planning officer.
Engineer it
Foundations sized for two floors, steels for any openings, and building control approval, all before anyone starts on site.
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 Knotty Ash

Who handles building regulations for a project in Knotty Ash?

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.

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

Knotty Ash 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.

Which postcodes do you cover around Knotty Ash?

We cover Knotty Ash (L14 and L28) and nearby places including Old Swan, West Derby and Childwall, plus the rest of Merseyside. The first site visit is free.

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.

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.

Nearby

We also cover places near Knotty Ash, including:

Other extensions in Knotty Ash

All two-storey extension services in Knotty Ash · Two-storey wraparound extensions across Merseyside

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