Extensions in Thornaby-on-Tees: design, planning and build
We design and build house extensions for homes in Thornaby-on-Tees and the surrounding County Durham area, with guide prices adjusted for the region.
- Postcode districtsTS17
- Price regionNorth East England (×0.91)
- Planning rulesEngland
- Site visitFree, no obligation
Planning rules in Thornaby-on-Tees
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a householder planning application.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
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).
Thornaby-on-Tees extension prices at a glance
Every figure below is a guide for Thornaby-on-Tees, adjusted for North East England build costs (×0.91) and including VAT. Design and council fees are shown separately on each page.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Orangery extensions | 16 m² | £40,500 – £51,000 |
| Side return extensions | 11 m² | £24,000 – £30,500 |
| Double-storey extensions | 32 m² | £52,000 – £68,500 |
| Conservatory replacement extensions | 14 m² | £27,000 – £35,500 |
| Kitchen extensions | 20 m² | £38,000 – £48,500 |
What works best for Thornaby-on-Tees houses?
The North East has many brick terraces, colliery-era housing and post-war semis, with rear extensions and kitchen extensions the most common requests.
For many houses here, single-storey rear extensions, utility and boot room extensions or kitchen extensions gives the most useful space for the budget.
Where we work near Thornaby-on-Tees
Site visits are available across Thornaby-on-Tees (TS17). We also work in nearby Stockton-on-Tees (3 miles), Yarm (3 miles), Billingham (4 miles), Darlington (10 miles), Hartlepool (11 miles). Middlesbrough, in North Yorkshire, is roughly 4 miles from Thornaby-on-Tees and also on our list.
Every extension type in Thornaby-on-Tees
- Utility and boot room extensions · from £12,500
- Double-storey extensions · from £34,500
- Porch extensions · from £3,600
- Extension plans and drawings · from £1,050
- Orangery extensions · from £27,000
- Timber frame extensions · from £19,000
- Wraparound extensions · from £32,500
- Side return extensions · from £16,000
- Extensions over a garage · from £21,500
- Annexe extensions · from £50,000
- Home office extensions · from £14,500
- Pitched roof extensions · from £20,000
- Conservatory replacement extensions · from £18,000
- Kitchen extensions · from £24,500
- Glass box extensions · from £27,000
- Side extensions · from £20,000
- Flat roof extensions · from £19,000
- Bungalow extensions · from £23,500
- Planning permission for extensions · from £300
- Bedroom extensions · from £23,500
- Single-storey rear extensions · from £19,000
- Building regulations for extensions · from £800
Free site visit
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
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
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions about extensions in Thornaby-on-Tees
How much does an extension cost in Thornaby-on-Tees?
Using our North East England factor (×0.91), a standard-spec single-storey extension of 20 m² is a guide £37,000 to £47,500 including VAT, and a 32 m² two-storey extension £52,000 to £68,500. Your written price follows the survey.
How long does an extension take in Thornaby-on-Tees?
Usually 2 to 4 months of design and approvals, then 10 to 16 weeks on site for a single-storey extension or 16 to 24 weeks for two storeys.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for Thornaby-on-Tees, and the guide-price tool gives a range for your own size and finish in about a minute.
Will my neighbours need to be told?
If you apply for planning or prior approval the council notifies them, and in England party wall notices may be needed for work near a shared boundary.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
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.