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Whiston, Merseyside

Single-storey rear extension in Whiston

For homes in Whiston, a single-storey rear extension is often the simplest way to gain space without moving. Ground-floor space across the back of the house, usually for a kitchen, dining or family room. We take it from survey to completion certificate.

Whiston is covered from our Merseyside round, including L35, WA9 and WA10. A single-storey rear extension in Whiston is mostly built from the garden side, so the house stays usable for most of the job.

Book a free site visit

Tell us about the house and we'll call to arrange a free, no-obligation visit.

How much does a single-storey rear extension cost in Whiston?

In Whiston, our guide for a single-storey rear extension is £1,790–£2,910 per square metre including VAT for a standard specification. North West prices sit below our West Midlands baseline; access on terraced streets is the main variable.

Single-storey rear extension prices in Whiston
SizeGuide price inc VAT
3 m wide × 4 m deep (12 m²)£21,500–£35,000
4 m wide × 5 m deep (20 m²)£35,500–£58,500
4 m wide × 6 m deep (24 m²)£43,000–£70,000

We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.

Do you need planning permission for a single-storey rear extension in Whiston?

Planning for a single-storey rear extension in Whiston follows the English householder rules.

In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is within 2 metres of a boundary.

England also has the larger home extension route: a single-storey rear extension of up to 6 metres on an attached house or 8 metres on a detached house, after prior approval from the council. The council notifies your neighbours and has 42 days to decide; the fee is £249 (£310 for applications made from 8 December 2026). The route is not available on designated land such as conservation areas.

Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.

What are homes in Whiston like to extend?

Whiston has long runs of terraced houses with back yards and alleys, plus 1930s semis further out. Yard extensions on terraces are often single-storey and close to both boundaries.

How a single-storey rear extension in Whiston comes together

  1. Free site visit

    We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.

  2. Drawings and budget

    Floor plans and elevations for the options, each with a guide price.

  3. Paperwork handled

    Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.

  4. Written price, then build

    Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.

Single-storey rear extensions near Whiston

Close by, we work in Prescot, about 0.8 miles away, and Rainhill, about 1.0 miles away.

Other work in Whiston:

All rear extensions in Whiston

FAQ

Single-storey rear extension questions in Whiston

How long does a rear extension take to build in Whiston?

Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.

Will I need a structural engineer?

Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.

Is a flat roof or a pitched roof better?

A warm flat roof keeps the extension low under first-floor windows and suits a roof lantern; a pitched or lean-to roof gives a vaulted ceiling. Both last for decades when built properly.

Who will build my extension?

Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.

Is the site visit in Whiston free?

Yes. We visit, measure up and talk through the options with no cost and no obligation.

What postcode areas do you cover around Whiston?

Including L35, WA9 and WA10, and the surrounding Merseyside area.

Next step

See what your rear extension would cost

Get a guide price online in a couple of minutes, or book a free site visit and we'll measure up and talk you through the planning route.

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