Side return extensions in Thornaby-on-Tees
From the first sketch to final sign-off, we plan and build side return extensions in Thornaby-on-Tees and the surrounding County Durham area.
- Guide price in Thornaby-on-TeesFrom £16,000 inc VAT
- PlanningOften permitted development; party wall notice usual
- Build time10–14 weeks on site
- Postcode districtsTS17
Covering Thornaby-on-Tees
Site visits are available across Thornaby-on-Tees (TS17). The same team covers Stockton-on-Tees (3 miles), Yarm (3 miles), Billingham (4 miles), Darlington (10 miles), all within easy reach.
For homes towards North Yorkshire, Middlesbrough is around 4 miles away. The North East has many brick terraces, colliery-era housing and post-war semis, with rear extensions and kitchen extensions the most common requests.
Planning rules that apply in Thornaby-on-Tees
In England a single-storey side return infill is often permitted development if it stays within the height limits and is no wider than half the width of the original house. Conservation areas, listed buildings and flats always need an application, and the boundary wall usually brings in the Party Wall Act.
The planning position for a specific Thornaby-on-Tees address depends on its history and any designations, which is why we check it at the first visit.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
Side return extension prices in Thornaby-on-Tees
These guide figures apply our North East England adjustment (×0.91) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Thornaby-on-Tees: £1,910 to £3,460 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 1.8 m × 4.5 m 8 m² | £16,000 – £19,500 | £17,000 – £22,000 | £21,500 – £28,000 |
| 2 m × 5.5 m 11 m² | £21,000 – £25,500 | £24,000 – £30,500 | £30,000 – £38,500 |
| 2.2 m × 7 m 15 m² | £28,500 – £34,500 | £32,500 – £41,000 | £40,500 – £52,000 |
For a figure based on your own dimensions, use our guide-price tool.
Included in a typical project
- Glazed, sloping or flat roof with rooflights
- Party wall notice support (England and Wales)
- Design to keep daylight in the middle of the house
- Survey of the outrigger, boundary wall and drainage
- New boundary wall or raised party wall
From first visit to completion
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Side return extension questions answered
How long does a side return extension take to build in Thornaby-on-Tees?
On site, typically 10 to 14 weeks once approvals are in place. Before that, allow 6–12 weeks design and approvals.
Will my neighbours in Thornaby-on-Tees be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Thornaby-on-Tees, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Will the kitchen be darker?
Not if the roof is designed well. A glazed roof or a line of rooflights along the boundary usually makes the room brighter than before.
Do side return extensions need planning permission?
In England many single-storey side returns fit within permitted development if they stay within the height limits and are no wider than half the width of the original house. Conservation areas, listed buildings and flats need an application. Other UK nations have their own rules, which we check.
Book a free site visit in Thornaby-on-Tees
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.