Covering Thornaby-on-Tees
Thornaby-on-Tees is about 41 miles north of York. We also cover Stockton-on-Tees (3 miles to the north), Billingham and Middlesbrough.
Homes in Yorkshire and the Humber
Stone-built terraces are typical of many West Yorkshire towns, while red brick dominates in Hull and much of South Yorkshire, so matching materials is a big part of designing an extension here.
What does a double-storey extension involve?
Two-storey work has to sit comfortably with the house and the neighbours, so most of the design effort goes into the roofline, window positions and how the new first floor connects to the landing. We handle the planning application, the structural design and the building control process, then build, roof and finish both floors.
- Measured survey, design and planning drawings
- Structural engineer’s design and calculations
- Foundations, steelwork, brick and block walls, roof
What will a double-storey extension cost?
Typical ranges for double-storey extensions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.
| Double-storey extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £2,400 to £2,900 per m² |
| Good specification | £2,900 to £3,400 per m² |
| High specification | £3,400 to £3,850 per m² |
Planning and building rules in Thornaby-on-Tees
Projects in England go through two separate checks. Planning (or confirmation that the work is permitted development) comes from the district, borough or unitary council, and building regulations approval comes from the council’s building control team or a registered building control approver. Where work touches a shared wall or digs near a neighbour’s foundations, the Party Wall etc. Act 1996 applies.
Two-storey rear extensions can sometimes be permitted development in England (no more than 3 m deep, at least 7 m from the rear boundary, roof pitch to match), but most two-storey and all two-storey side extensions need householder planning permission.
What should I think about before starting?
- Side extensions close to a boundary are often set back or stepped down so they do not create a terraced effect.
- The new roof is tied into the old one, so roof tiles and ridge details need to match.
From first call to completion
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
- Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
Questions about a double-storey extension in Thornaby-on-Tees
Does a two-storey extension need planning permission?
Usually yes. In England some two-storey rear extensions are permitted development, but side extensions over one storey always need planning permission.
Is a two-storey extension better value than a single-storey one?
Per square metre, usually yes, because the foundations and roof serve two floors of space.
Can you visit a house in Thornaby-on-Tees to quote?
Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.
Double-storey extensions in nearby towns
- Double-storey extensions in Stockton-on-Tees
- Double-storey extensions in Billingham
- Double-storey extensions in Middlesbrough
- Double-storey extensions in Darlington
Learn more about double-storey extensions, or see every project we cover in Thornaby-on-Tees.

