Thornaby-on-Tees flat roof extensions, designed and built
Thornaby-on-Tees homeowners can use us for the whole flat roof extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in Thornaby-on-TeesFrom £19,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsTS17
Planning and approvals 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.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Included in a typical project
- Lanterns or rooflights with upstands
- Falls and outlets designed to drain properly
- Parapets or edge trims and flashings to the house
- Warm-roof design with insulation above the deck
Height is often what decides a flat roof. Under first-floor windows, a pitched roof may not fit at all; a flat roof keeps the extension low while still giving a good ceiling height inside.
Local to Thornaby-on-Tees
Across TS17, we can visit, measure and advise. The same team covers Stockton-on-Tees (3 miles), Yarm (3 miles), Billingham (4 miles), Darlington (10 miles), all within easy reach.
Middlesbrough, in North Yorkshire, is roughly 4 miles from Thornaby-on-Tees and also on our list. Across the North East, houses often have rear yards or modest gardens, so compact, well-lit single-storey extensions make the biggest difference.
Flat roof extension prices in Thornaby-on-Tees
For Thornaby-on-Tees we adjust our national guide rates by ×0.91, the factor we use for North East England. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Thornaby-on-Tees: £1,590 to £3,050 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £19,000 – £22,500 | £22,000 – £28,500 | £28,000 – £37,000 |
| 4 m × 5 m 20 m² | £31,500 – £37,500 | £37,000 – £47,500 | £47,000 – £61,000 |
| 5 m × 6 m 30 m² | £47,500 – £56,000 | £55,500 – £71,000 | £70,500 – £91,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
How the project works
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Questions people ask about flat roof extensions
Do I need building regulations approval in Thornaby-on-Tees?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Do you cover all of Thornaby-on-Tees?
Yes. We cover Thornaby-on-Tees and the surrounding parts of County Durham. Site visits are free and there is no obligation.
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 walk on a flat roof extension?
Only for maintenance unless it is designed as a terrace. A roof terrace or balcony needs planning permission and a different structure.
Are flat roof extensions cheaper?
Usually slightly, because there is less roof structure and no tiles. Our guide range is about £1,590 to £3,050 per m² including VAT.
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.