Cramlington, Northumberland
Semi-detached rear extension in Cramlington
Single or two-storey extensions for semi-detached houses, with side access and one party wall. If you live in Cramlington and want to know what a semi-detached rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
Cramlington and its postcode districts NE22, NE23 and NE24 are part of our Northumberland coverage. Where a Cramlington 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 Cramlington?
A semi-detached rear extension in Cramlington is priced at £1,710–£2,790 per square metre including VAT as a guide, before kitchen fit-out and fees. North East prices are among the lowest in our range; former mining ground is the main foundation variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £20,500–£33,500 |
| 4 m wide × 5 m deep (20 m²) | £34,000–£56,000 |
| 4 m wide × 6 m deep (24 m²) | £41,000–£67,000 |
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 Cramlington?
The planning route for a semi-detached rear extension in Cramlington is set by England's householder rules and your council.
Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it is 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 Cramlington like to extend?
Brick terraces, colliery houses and post-war semis make up much of Cramlington. Former mining areas often need a coal mining risk check before foundations are designed.
How a semi-detached rear extension in Cramlington 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.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
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 Cramlington
We also build rear extensions for semi-detached houses in nearby Bedlington (3.1 miles) and Blyth (4.1 miles).
- Semi-detached rear extension in Bedlington
- Semi-detached rear extension in Blyth
- Semi-detached rear extension in Gosforth
- Semi-detached rear extension in Ashington
- Semi-detached rear extension in Whitley Bay
Other work in Cramlington:
FAQ
Semi-detached rear extension questions in Cramlington
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
How long does a semi extension take?
10 to 16 weeks on site for a single-storey extension.
Do I need planning permission for a rear extension in Cramlington?
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.
Can you match the brick or stone on my Cramlington house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.