Durham flat roof extensions, designed and built
We design and build flat roof extensions for houses in Durham, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in DurhamFrom £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 districtsDH1
Covering Durham
Site visits are available across Durham (DH1). Neighbouring towns we cover include Chester-le-Street (6 miles), Stanley (8 miles), Bishop Auckland (9 miles), Peterlee (10 miles).
The North East has many brick terraces, colliery-era housing and post-war semis, with rear extensions and kitchen extensions the most common requests.
Flat roof extension prices in Durham
Prices below are for Durham, using the North East England factor of ×0.91. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Durham: £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.
Planning rules that apply in Durham
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.
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.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
What is included
- Parapets or edge trims and flashings to the house
- Warm-roof design with insulation above the deck
- Lanterns or rooflights with upstands
- Membrane choice: single-ply, EPDM or GRP
- Falls and outlets designed to drain properly
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
We visit your Durham home, measure up, talk through what you want and check the planning position.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions people ask about flat roof extensions
Who do I contract with for a flat roof extension in Durham?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Will my neighbours in Durham 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 Durham, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
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.
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.
Book a free site visit in Durham
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.