Two-storey extensions for detached houses in Hale Barns

Before you start in Hale Barns, here's what applies.

Postcode districts: M90
County / area: Greater Manchester, 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: Hale (Greater Manchester) (1 mile), Altrincham (1.9 miles), Timperley (2.3 miles)
Distance to Manchester: about 8.3 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.

Around Hale Barns we also work in Hale (Greater Manchester), Altrincham and Timperley, and across the rest of Greater Manchester. Postcode district in and near Hale Barns: M90.

What it costs in Hale Barns

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. 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	A 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 Hale Barns

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 Hale Barns homes

Keeping it subordinate

Large detached houses can take a large extension, but councils still expect it to look secondary to the main house. A lower ridge, a modest set-back at the front and matching materials keep the proportions right, even on a wide plot.

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

Visit and first ideas
One of our team visits your house in Hale Barns, checks the walls, roof and drains, and sketches out options with you.
Drawings, then consent
We draw the scheme, check it against the rules in England, and take it through the right consent with the council.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
On site
One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.

Questions about two-storey extensions for detached houses in Hale Barns

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.

Which postcodes do you cover around Hale Barns?

We cover Hale Barns (M90) and nearby places including Hale (Greater Manchester), Altrincham and Timperley, plus the rest of Greater Manchester. The first site visit is free.

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

Hale Barns 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 big an extension can a detached house take?

It depends on the plot, the boundaries and local design policy rather than a fixed limit. Under permitted development in England, extensions must not cover more than 50% of the land around the original house. With planning permission, the council judges size on proportion, neighbours and the character of the area.

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

The same service in neighbouring towns:

Other extensions in Hale Barns

All two-storey extension services in Hale Barns · Two-storey extensions for detached houses across Greater Manchester

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