Stockton-on-Tees, County Durham
Semi-detached rear extension in Stockton-on-Tees
Single or two-storey extensions for semi-detached houses, with side access and one party wall. We design, get the approvals for and build rear extensions for semi-detached houses in Stockton-on-Tees and the surrounding area, with one contract from the first survey to building control sign-off.
We cover Stockton-on-Tees (TS17, TS18, TS19 and TS20) as part of our County Durham work. Where a Stockton-on-Tees 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 Stockton-on-Tees?
In Stockton-on-Tees, our guide for a semi-detached rear extension is £1,710–£2,790 per square metre including VAT for a standard specification. 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 Stockton-on-Tees?
Planning for a semi-detached rear extension in Stockton-on-Tees follows the English householder rules.
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.
England's rules allow a rear extension of more than one storey without an application only when it is no deeper than 3 metres and at least 7 metres from the boundary opposite the rear wall, and never on designated land. Most two-storey schemes need householder planning permission.
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 Stockton-on-Tees like to extend?
Terraces and semis are typical around Stockton-on-Tees. On terraces a single-storey rear extension across the back yard is usually the practical choice; semis often have room for more.
How a semi-detached rear extension in Stockton-on-Tees comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
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 Stockton-on-Tees
Close by, we work in Billingham, about 1.8 miles away, and Thornaby-on-Tees, about 2.5 miles away.
- Semi-detached rear extension in Billingham
- Semi-detached rear extension in Thornaby-on-Tees
- Semi-detached rear extension in Ingleby Barwick
- Semi-detached rear extension in Middlesbrough
- Semi-detached rear extension in Yarm
Other work in Stockton-on-Tees:
FAQ
Semi-detached rear extension questions in Stockton-on-Tees
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.
Do I need planning permission for a rear extension in Stockton-on-Tees?
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.
What if my neighbour has already extended?
That can make a matching depth easier to justify. We measure theirs at the survey.
How much does a semi-detached rear extension cost in Stockton-on-Tees?
As a guide, £1,710–£2,790 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £20,500–£33,500 at that rate. Your written price follows the survey.
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.
How long does a rear extension take to build in Stockton-on-Tees?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.