Two-storey extensions for semi-detached houses in Retford

What we'd confirm first for a project in Retford.

Postcode districts: DN10 and DN22
County / area: Nottinghamshire, England
Price region: East Midlands
Guide price: £55,000–£74,000 (£1,960–£2,650 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: Worksop (7.6 miles), Gainsborough (8.4 miles), Boughton (8.6 miles)
Distance to Nottingham: about 26.9 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.

Around Retford we also work in Worksop, Gainsborough and Boughton, and across the rest of Nottinghamshire. Postcode districts in and near Retford: DN10 and DN22.

What it costs in Retford

A guide price for Retford: around £55,000–£74,000 for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). That works out at £1,960–£2,650 per m² of new floor space, including VAT at 20%. Kitchens, bathroom fittings and flooring are priced separately so you can compare like with like.

Spec	Per m²	A 4 m × 3.5 m footprint on two floors (28 m² of new floor space)
Essential	£1,800–£2,430 per m²	£50,500–£68,000
Standard	£1,960–£2,650 per m²	£55,000–£74,000
Premium	£2,350–£3,180 per m²	£66,000–£89,000

Planning and building regulations in Retford

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 Retford 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.

The attached neighbour's light

A two-storey rear extension next to the party wall can take light from the neighbour's rear windows. Councils often use a 45-degree test, so the first floor may need to be shorter than the ground floor or set in from the shared boundary.

How we'd run your project

Look at the house
We start in Retford with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Get it approved
Once you're happy with the design we submit it to the council for Retford and deal with any questions from the planning officer.
Fixed price in writing
With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.
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 semi-detached houses in Retford

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

Our guide for the East Midlands, which covers Retford, is £1,960–£2,650 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 £55,000–£74,000. 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 Retford?

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.

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.

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.

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.

Nearby

Other towns near Retford:

Other extensions in Retford

All two-storey extension services in Retford · Two-storey extensions for semi-detached houses across Nottinghamshire

Tell us about your house in Retford and we'll call you back to arrange a free, no-obligation visit.