Middlesbrough, North Yorkshire
Semi-detached rear extension in Middlesbrough
Thinking about a semi-detached rear extension in Middlesbrough? 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.
Middlesbrough sits in North Yorkshire, with postcode districts including TS1, TS2, TS3 and TS4. Where a Middlesbrough 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 Middlesbrough?
For Middlesbrough we work from the North East England rate: £1,710–£2,790 per square metre of new floor, including VAT, 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 Middlesbrough?
Planning for a semi-detached rear extension in Middlesbrough follows the English householder rules.
In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is 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.
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 Middlesbrough like to extend?
Terraces and semis are typical around Middlesbrough. 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 Middlesbrough comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
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.
Semi-detached rear extensions near Middlesbrough
Neighbouring places we cover include Billingham (2.4 miles) and Stockton-on-Tees (3.4 miles).
- Semi-detached rear extension in Billingham
- Semi-detached rear extension in Stockton-on-Tees
- Semi-detached rear extension in Thornaby-on-Tees
- Semi-detached rear extension in Ingleby Barwick
- Semi-detached rear extension in Yarm
Other work in Middlesbrough:
FAQ
Semi-detached rear extension questions in Middlesbrough
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.
How long does a rear extension take to build in Middlesbrough?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
How far can I extend a semi without planning?
3 metres under permitted development in England, or up to 6 metres with prior approval, outside designated land.
How much does a semi-detached rear extension cost in Middlesbrough?
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.
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.
Is the site visit in Middlesbrough free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.