Radcliffe · Greater Manchester

Two-storey extensions for semi-detached houses in Radcliffe

Adding a two-storey extension for a semi-detached house in Radcliffe gives you two new rooms stacked on one footprint. Here's how we'd approach it, what it typically costs and the rules that apply in England.

Useful details for planning a two-storey extension for a semi-detached house in Radcliffe.

Postcode districts
M26
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
Whitefield (1.3 miles), Little Lever (2.2 miles), Prestwich (2.6 miles)
Distance to Manchester
about 6.6 miles
First visit
Free, no obligation

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

This service suits you if you own a semi-detached house and want to add bedrooms and living space without moving. On a semi, the main questions are which side to build on and how to treat the attached neighbour. You get a survey, design options, the approvals your nation needs and the build, carried out by vetted teams working under S&K.

We cover postcode district M26 in and around Radcliffe, along with neighbouring Whitefield, Little Lever and Prestwich.

What it costs in Radcliffe

A guide price for Radcliffe: around £53,000–£72,000 for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). That works out at £1,900–£2,560 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.

SpecPer m²A 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 Radcliffe

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 Radcliffe homes

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.

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.

How we'd run your project

  1. Understand the brief

    At your home in Radcliffe we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.

  2. Get it approved

    Once you're happy with the design we submit it to the council for Radcliffe and deal with any questions from the planning officer.

  3. Fixed price in writing

    With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.

  4. 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 Radcliffe

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

Radcliffe 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 semi-detached house cost in Radcliffe?

Our guide for North West England, which covers Radcliffe, 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.

Who handles building regulations for a project in Radcliffe?

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.

What if my neighbour has already extended?

That often helps. An existing extension next door can reduce the effect of yours on their light, and may show what the council accepts on your street. It can also mean building alongside their wall, so we check its position, foundations and any windows facing your plot at the survey.

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

Close to Radcliffe? We work across the area, including:

Other extensions in Radcliffe

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

The quickest next step is a visit. We'll look at your house in Radcliffe and give you an honest view of the options.

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