Mansfield, Nottinghamshire
Semi-detached rear extension in Mansfield
Thinking about a semi-detached rear extension in Mansfield? Single or two-storey extensions for semi-detached houses, with side access and one party wall. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
Mansfield is covered from our Nottinghamshire round, including NG18 and NG19. Where a Mansfield semi already has a small lean-to at the back, we usually replace it rather than extend it.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a semi-detached rear extension cost in Mansfield?
In Mansfield, our guide for a semi-detached rear extension is £1,840–£3,010 per square metre including VAT for a standard specification. East Midlands prices sit a little below our West Midlands baseline.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £22,000–£36,000 |
| 4 m wide × 5 m deep (20 m²) | £37,000–£60,000 |
| 4 m wide × 6 m deep (24 m²) | £44,000–£72,000 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a semi-detached rear extension in Mansfield?
Whether your semi-detached rear extension in Mansfield needs a planning application depends on its size, your house and any local restrictions.
English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.
A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.
England also has the larger home extension route: a single-storey rear extension of up to 6 metres on an attached house or 8 metres on a detached house, after prior approval from the council. The council notifies your neighbours and has 42 days to decide; the fee is £249 (£310 for applications made from 8 December 2026). The route is not available on designated land such as conservation areas.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Mansfield like to extend?
Mansfield has plenty of inter-war semis and bungalows, and single-storey rear extensions suit both.
How a semi-detached rear extension in Mansfield comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Approvals
Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Semi-detached rear extensions near Mansfield
We also build rear extensions for semi-detached houses in nearby Mansfield Woodhouse (2.2 miles) and Sutton in Ashfield (2.6 miles).
- Semi-detached rear extension in Mansfield Woodhouse
- Semi-detached rear extension in Sutton in Ashfield
- Semi-detached rear extension in Kirkby in Ashfield
- Semi-detached rear extension in Shirebrook
- Semi-detached rear extension in Pinxton
Other work in Mansfield:
FAQ
Semi-detached rear extension questions in Mansfield
Is the site visit in Mansfield free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
What postcode areas do you cover around Mansfield?
Including NG18 and NG19, and the surrounding Nottinghamshire area.
Can I match pebbledash or render?
Yes. Many semis are refinished with new render across the whole back elevation so old and new match.
Do you handle building control in Mansfield?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Do I need planning permission for a rear extension in Mansfield?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.