Thornaby-on-Tees, North Yorkshire
Single-storey rear extension in Thornaby-on-Tees
Ground-floor space across the back of the house, usually for a kitchen, dining or family room. If you live in Thornaby-on-Tees and want to know what a single-storey rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
We cover Thornaby-on-Tees (TS16, TS17 and TS18) as part of our North Yorkshire work. A depth of 3 to 4 metres keeps many single-storey rear extensions in Thornaby-on-Tees within permitted development, subject to the house's planning history.
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 single-storey rear extension cost in Thornaby-on-Tees?
A single-storey rear extension in Thornaby-on-Tees 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 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a single-storey rear extension in Thornaby-on-Tees?
The planning route for a single-storey rear extension in Thornaby-on-Tees is set by England's householder rules and your council.
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.
If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Thornaby-on-Tees like to extend?
Terraces and semis are typical around Thornaby-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 single-storey rear extension in Thornaby-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.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Single-storey rear extensions near Thornaby-on-Tees
Neighbouring places we cover include Ingleby Barwick (1.0 miles) and Stockton-on-Tees (2.5 miles).
- Single-storey rear extension in Ingleby Barwick
- Single-storey rear extension in Stockton-on-Tees
- Single-storey rear extension in Yarm
- Single-storey rear extension in Billingham
- Single-storey rear extension in Middlesbrough
Other work in Thornaby-on-Tees:
FAQ
Single-storey rear extension questions in Thornaby-on-Tees
Is the site visit in Thornaby-on-Tees free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
How long does a rear extension take to build in Thornaby-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.
Will the extension make the room behind it dark?
Not if it is designed well. Rooflights or a lantern over the old back room, and a wide opening into it, keep daylight reaching the middle of the house.
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 much does a single-storey rear extension cost in Thornaby-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.