Two-storey extensions in Thornaby-on-Tees
Everything for a two-storey extension in Thornaby-on-Tees, in one place: types, guide prices for North East England, the approval rules in England and how to get started.
Thornaby-on-Tees at a glance
- Postcode districts
- TS17
- Area
- County Durham, England
- Price region
- North East England
- Nearest towns
- Stockton-on-Tees (2.5 miles), Yarm (3.1 miles), Billingham (3.9 miles), Middlesbrough (4 miles)
- Distance to Darlington
- about 10.1 miles
- Approvals
- Two-storey rear: up to 3 m deep and 7 m from the rear boundary under permitted development. Side, wraparound and front: planning permission.
Thornaby-on-Tees sits about 10.1 miles from Darlington. Closer to home, Stockton-on-Tees is 2.5 miles away and Yarm 3.1 miles.
Extensions available in Thornaby-on-Tees
Two-storey rear extensions
Thornaby-on-Tees guide price from £50,500, Standard spec.
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Two-storey side extensions
Our North East England guide starts at £77,500 for this type.
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Two-storey wraparound extensions
Design, approvals and build for Thornaby-on-Tees homes. Guide from £108,500.
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Part single, part two-storey extensions
Guide from £65,000 in Thornaby-on-Tees, including VAT.
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Extensions over a garage
From £28,500 in Thornaby-on-Tees. Free visit to firm it up.
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First-floor extensions
Thornaby-on-Tees guide price from £22,500, Standard spec.
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Two-storey extensions for semi-detached houses
Thornaby-on-Tees guide price from £50,500, Standard spec.
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Two-storey extensions for detached houses
Thornaby-on-Tees guide price from £77,500, Standard spec.
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Kitchen extensions with bedrooms above
Our North East England guide starts at £50,500 (before kitchen units) for this type.
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Extra bedroom and en-suite extensions
Design, approvals and build for Thornaby-on-Tees homes. Guide from £50,500 (plus en-suite).
Learn moreWhich type suits your house?
The boundaries usually decide it. Two-storey work close to a neighbour needs careful design for light and privacy, so at the visit in Thornaby-on-Tees we measure distances to every boundary before suggesting a type.
Also available in County Durham
- Two-storey front extensions
- Two-storey extensions for end-of-terrace houses
- Two-storey annexe extensions
- Garage conversions with a room above
- Two-storey extension plans and drawings
- Planning permission for two-storey extensions
- Structural engineering for two-storey extensions
- Building regulations for two-storey extensions
- Party wall notices for extensions
- Design and build two-storey extensions
Rules for Thornaby-on-Tees
Thornaby-on-Tees is in England. Two-storey rear: up to 3 m deep and 7 m from the rear boundary under permitted development. Side, wraparound and front: planning permission. Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.
The full England rules explained
Questions about extensions in Thornaby-on-Tees
Do you cover Thornaby-on-Tees?
Yes. We cover Thornaby-on-Tees (TS17) and the surrounding area, including Stockton-on-Tees and Yarm. The first site visit is free.
What does a two-storey extension cost in Thornaby-on-Tees?
Using our North East England guide, a two-storey rear extension with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) is about £50,500–£68,000 including VAT. An extension over a garage is about £28,500–£41,500.
Which other places near Thornaby-on-Tees do you cover?
Everywhere around it, including Stockton-on-Tees (2.5 miles), Yarm (3.1 miles) and Billingham (3.9 miles), and the rest of County Durham.