Two-storey extensions for semi-detached houses in Swinton

Swinton: the key facts for this kind of project.

Postcode districts: M27
County / area: Greater Manchester, England
Price region: North West England
Guide price: £53,000–£72,000 (£1,900–£2,560 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: Eccles (1.3 miles), Walkden (2.4 miles), Salford (2.6 miles)
Distance to Manchester: about 4.8 miles
First visit: Free, no obligation

About a two-storey extension for a semi-detached house

A two-storey extension for a semi-detached house is a two-floor addition to the rear, the open side, or both, designed around the attached neighbour on one side. The rear is often the simplest option and can sometimes be permitted development, while a side extension uses the gap on the detached side. Both need care with the shared party wall and the neighbour's light.

Around Swinton we also work in Eccles, Walkden and Salford, and across the rest of Greater Manchester. Postcode district in and near Swinton: M27.

What it costs in Swinton

Expect a two-storey extension for a semi-detached house in Swinton to land somewhere around £53,000–£72,000 for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). Our North West England guide rate is £1,900–£2,560 per m², including VAT. Keep a contingency of around 10% for things nobody can see until the ground is opened up.

Spec	Per m²	A 4 m × 3.5 m footprint on two floors (28 m² of new floor space)
Essential	£1,750–£2,360 per m²	£49,000–£66,000
Standard	£1,900–£2,560 per m²	£53,000–£72,000
Premium	£2,280–£3,080 per m²	£64,000–£86,000

Planning and building regulations in Swinton

In England, a two-storey rear extension on a semi can be permitted development if it goes no more than 3 m beyond the original rear wall and stays 7 m from the rear boundary, with matching materials and roof pitch. A two-storey side or wraparound extension always needs planning permission, costing £548 (or £575 for applications made from 8 December 2026). Protected areas such as conservation areas exclude two-storey rear permitted development.

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 Swinton homes

Rear, side or both

On a semi, a rear extension sits against the attached neighbour, while a side extension faces the detached neighbour and the street. We compare the space, cost and approval route for each, and for a wraparound, before you commit to one design.

Keeping the pair balanced

Semis are designed as matching pairs, and a side extension changes that balance. Setting the side extension back from the front wall and keeping its ridge lower helps the pair still read as a pair, which councils' design guides commonly ask for.

How we'd run your project

Look at the house
We start in Swinton with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Choose the approval route
Some designs fit permitted development, most need a householder application. We decide which applies in England before drawing in detail.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
Build
Foundations, walls, floor, roof, windows, then first and second fix. We break through into the house as late as we can.

Questions about two-storey extensions for semi-detached houses in Swinton

How long does a two-storey extension for a semi-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.

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

Our guide for North West England, which covers Swinton, is £1,900–£2,560 per m² including VAT. A typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £53,000–£72,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

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

Swinton 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.

Does a two-storey extension add value to a semi-detached house?

It usually adds value, but the gain is never certain. Nationwide's 2025 research found that 10% more floor area was linked to about 5% higher value, and that adding a double bedroom and bathroom to a three-bed, one-bathroom house could add up to 24%. Every street has a ceiling price, so check local sales first.

Will a side extension make my semi look like a terrace?

It can if it fills the whole gap to the boundary at first floor and the neighbour does the same. Many councils ask for a first-floor gap to the side boundary or a set-back for this reason. We design the extension to keep the semi reading as one of a pair.

Nearby

Other towns near Swinton:

Other extensions in Swinton

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

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