Brent at a glance
- Postcode districts
- HA9, HA0, NW10, NW9, NW2, NW4
- Council area
- London Borough of Brent
- Building approval
- London Borough of Brent building control, or a registered building control approver
- Guide price region
- London (+20% on West Midlands rates)
What makes a good extension roof in Brent?
Extension roofs in Brent are often replaced because the original was built cheaply: thin chipboard decks, little or no insulation and felt turned up the wall without a proper flashing. Twenty or thirty years on, those weaknesses show up as leaks at the back wall and a cold, damp ceiling.
In and around Brent, flat roofs are typically found on kitchen extensions and roof terraces behind period houses, and on shops with flat-roofed stores below flats above. The Thames basin is one of the drier parts of Britain at roughly 730 mm of rain a year, but summer heat is the bigger test here: dark membranes on south-facing roofs swing a long way in temperature.
How much does a new extension roof cost in Brent?
At London guide rates, a 20 m² extension roof in EPDM with a new deck and insulation comes to £3,350–£5,850 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 | £3,350–£5,850 |
| Extension (20 m²), GRP, new deck + insulation | £3,600–£6,450 |
| Extension (20 m²), EPDM, insulation + 1 rooflight upstand | £3,600–£6,300 |
| Single garage (18 m²), EPDM rubber | £1,900–£3,350 |
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?
- Staged strip-out so the room stays weathertight
- Falls set away from the house wall
- New deck, vapour control layer and warm-roof insulation
- Building control handled where needed, and a written workmanship guarantee
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?
- Harrow · 3 mi
- Ealing · 3 mi
- Hammersmith and Fulham · 5 mi
- Kensington and Chelsea · 6 mi
- Westminster · 6 mi
- Camden · 6 mi
Extension and kitchen roofs in Brent: questions
Do you cover Brent?
Yes. Brent is part of our London coverage, including postcode districts HA9, HA0, NW10, NW9, NW2, NW4. 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 Brent?
Where the work needs approval it goes to London Borough of Brent 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 Brent?
£3,350–£5,850 for a 20 m² extension roof in EPDM with a new deck and insulation, at London guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
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.
Why does my extension ceiling get damp in winter if the roof isn't leaking?
That is often condensation in a cold roof, where warm, moist air reaches the cold underside of the deck. A warm-roof replacement with a vapour control layer usually solves it.