Didcot at a glance
- Postcode districts
- OX11
- Population
- about 29,341 (GeoNames)
- Council area
- South Oxfordshire District Council
- Building approval
- South Oxfordshire District Council building control, or a registered building control approver
- Nearest main town
- Oxford, about 10 miles
- Guide price region
- South East (+10% on West Midlands rates)
What makes a good extension roof in Didcot?
If you're fitting a new kitchen under an extension in Didcot, that's a good time to replace the roof. It makes sense to rebuild the roof before fitting new units, ceilings and lighting below, and the insulation upgrade makes the room more comfortable all year.
Didcot's flat roofs are mostly on 1960s and 1970s link-detached houses with flat-roofed garages and porches, with plenty on shops with flat-roofed rear stores below flats too. Much of the South East sits in the drier Thames catchment at roughly 730 mm of rain a year, so the usual failures are at joints, upstands and outlets rather than from sheer volume of rain.
How much does a new extension roof cost in Didcot?
At South East guide rates, a 20 m² extension roof in EPDM with a new deck and insulation comes to £3,100–£5,350 including VAT. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Extension (20 m²), EPDM, new deck + insulation | £3,100–£5,350 |
| Extension (20 m²), GRP, new deck + insulation | £3,300–£5,900 |
| Extension (20 m²), EPDM, insulation + 1 rooflight upstand | £3,300–£5,750 |
| Single garage (18 m²), EPDM rubber | £1,750–£3,100 |
How long will my kitchen be disrupted by a new roof?
Most single-storey extension roofs are replaced in two to four working days, depending on size, rooflights and weather. The kitchen usually stays in use throughout.
Expect noise during the strip-out, and occasional dust through gaps around old rooflights, so it helps to cover worktops and move anything fragile off high shelves. We strip only what we can make weathertight by the end of each day. If a rooflight or lantern is being lifted and refitted, there may be a temporary cover over the opening for a short time. Resin systems smell while they cure, so keep the windows below the roof closed on that day.
What's included?
- New abutment upstand and flashing, plus rebuilt rooflight kerbs
- New deck, vapour control layer and warm-roof insulation
- Free survey of the roof, abutment and room below
- Falls set away from the house wall
Building regulations in England
Replacing more than half of a flat roof over a heated room usually counts as renovating a thermal element, so the roof is insulated to around 0.16 W/m²K where that's technically and economically feasible, and the work is notified to building control: the council or a registered building control approver, unless a registered competent person self-certifies it. A roof on a new extension is built to 0.15 W/m²K. Patch repairs, and most unheated detached garages, don't trigger the upgrade. Structural changes, or a new covering that adds 15% or more to the roof's weight, also need approval. More on the rules.
Which nearby areas do we also cover?
Extension and kitchen roofs in Didcot: questions
Do you cover Didcot?
Yes. Didcot is part of our Oxfordshire coverage, including postcode districts OX11. Surveys and roofs are carried out by vetted roofing teams working under S&K Property Investments and Improvement Ltd.
Who checks building regulations for a flat roof in Didcot?
Where the work needs approval it goes to South Oxfordshire District Council building control, or a registered building control approver. We tell you at the survey whether your job needs it and deal with the paperwork as part of the quote.
How much does a new extension roof cost in Didcot?
£3,100–£5,350 for a 20 m² extension roof in EPDM with a new deck and insulation, at South East guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Is EPDM or GRP better for a kitchen extension?
Neither is better in every case. EPDM suits simple rectangular roofs with few details, while GRP is often chosen where there are rooflights, corners or occasional foot traffic.
How do I know my extension roof needs replacing rather than repairing?
Repeated leaks, a soft deck, wet insulation or widespread cracking point to replacement. A single defect on a dry, sound roof can usually be repaired.