Golborne · Merseyside

Two-storey extensions for detached houses in Golborne

Want to stay in Golborne but need more space? A two-storey extension for a detached house adds floor area on two levels without giving up much garden. Here's what's involved.

The basics for Golborne at a glance.

Postcode districts
WA12
County / area
Merseyside, England
Price region
North West England
Guide price
£82,000–£109,500 (£1,950–£2,610 per m²)
Approval route
Depends on position: a two-storey rear extension may be permitted development (3 m deep, 7 m from the rear boundary); a two-storey side extension needs planning permission.
Nearest towns
Newton-le-Willows (1.9 miles), Abram (2.2 miles), Ashton-in-Makerfield (2.2 miles)
Distance to Liverpool
about 16.4 miles
First visit
Free, no obligation

About a two-storey extension for a detached house

This service suits you if you own a detached house and want a substantial amount of extra space, whether a side extension over a drive, a rear extension into the garden or a wraparound. You get a survey of the whole plot, options that compare layouts and costs, the approvals your nation needs, structural design and the build, carried out by vetted teams working under S&K.

We cover postcode district WA12 in and around Golborne, along with neighbouring Newton-le-Willows, Abram and Ashton-in-Makerfield.

What it costs in Golborne

Using our North West England rates, a two-storey extension for a detached house with a 3 m × 7 m footprint on two floors (42 m² of new floor space) comes to about £82,000–£109,500, including VAT. Bigger or more glazed designs cost more per m². We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.

SpecPer m²A 3 m × 7 m footprint on two floors (42 m² of new floor space)
Essential£1,790–£2,400 per m²£75,500–£101,000
Standard£1,950–£2,610 per m²£82,000–£109,500
Premium£2,340–£3,130 per m²£98,000–£131,500

Planning and building regulations in Golborne

In England, a two-storey rear extension on a detached house can be permitted development within 3 m of the original rear wall and at least 7 m from the rear boundary, with matching roof pitch and materials, outside protected areas. Any two-storey side or wraparound extension needs planning permission, costing £548 (or £575 for applications made from 8 December 2026), with a decision due 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 Golborne homes

Larger spans and steelwork

Bigger extensions often mean wider openings and longer spans, which need more steel and sometimes a steel frame. The engineer designs these early, because the size of the steel affects ceiling heights, floor depths and the cost.

Choosing the best side

On a detached house you can often extend on either side or the rear. We look at orientation for daylight, where the stairs and landing are, the distance to each boundary, drains and trees, so the extension goes where it adds the most useful space.

How we'd run your project

  1. Measure and listen

    A visit to Golborne to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.

  2. Drawings and permission

    Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Golborne.

  3. Engineer it

    Foundations sized for two floors, steels for any openings, and building control approval, all before anyone starts on site.

  4. Finish and certify

    Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Questions about two-storey extensions for detached houses in Golborne

Do I need planning permission for a two-storey extension for a detached house in Golborne?

Golborne is in England, so England planning rules apply. Depends on position: a two-storey rear extension may be permitted development (3 m deep, 7 m from the rear boundary); a two-storey side extension needs planning permission. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

How much does a two-storey extension for a detached house cost in Golborne?

Our guide for North West England, which covers Golborne, is £1,950–£2,610 per m² including VAT. A typical project with a 3 m × 7 m footprint on two floors (42 m² of new floor space) comes to about £82,000–£109,500. 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 extension for a detached house 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.

Is a detached house extension a better investment than moving?

It often costs less than the gap between your house and a larger one nearby, once property tax, legal fees and removal costs are counted, but that depends on your area. Extending also has limits: every street has a ceiling price. We give you build costs so you can compare them with local asking prices.

Can I extend a detached house on both sides?

Sometimes. With planning permission, a council may accept extensions on both sides if the house stays well proportioned and keeps gaps to the boundaries. It is more common to extend on one side and the rear, or with a wraparound. We look at the plot as a whole before suggesting more than one extension.

Nearby

Other towns near Golborne:

Other extensions in Golborne

All two-storey extension services in Golborne · Two-storey extensions for detached houses across Merseyside

Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Golborne.

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