Extension and kitchen roofs across Hampshire

Guide price

£3,100–£5,350

Survey

Free for new and replacement roofs

Quote

Fixed, in writing

Coverage

England, Wales, Scotland, NI

How much does a new extension roof cost in Hampshire?

Guide prices including VAT at South East rates. The fixed price comes after a free survey for new and replacement roofs.

Which flat roofs are common in Hampshire?

Flat roofs in Hampshire sit on low-rise post-war blocks of flats, lock-up garage blocks on estates and newer estates where the first extension roofs are now being replaced. 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. Approximate 1991–2020 regional averages based on Met Office data.

Building regulations in England

Replacing more than half of a roof over a heated room usually counts as renovating a thermal element, so it is insulated to current standards and notified to building control. Renovated roofs over heated rooms are insulated to around 0.16 W/m²K where that's feasible, and new extension roofs are built to 0.15 W/m²K. In Hampshire the application goes to Southampton City Council, Portsmouth City Council, Basingstoke and Deane Borough Council and 10 other councils. More on the rules.

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.

Does an extension roof replacement need building regulations?

Usually, yes. An extension roof over a heated room is a thermal element, so replacing most of it typically brings insulation requirements and an approval route.

In England, renovating more than half of the roof means upgrading it towards 0.16 W/m²K where that is technically, functionally and economically feasible. The approval comes from building control or a competent person scheme. A brand-new extension roof is designed to 0.15. Wales usually requires approval for most re-roofing, with a renovation target of 0.16 and a new-extension target of 0.13. Scotland handles this through building standards and the warrant process, and Northern Ireland through district council building control.

Planning is not normally needed to re-cover an extension roof that looks broadly the same afterwards. Turning the roof into a terrace is another matter. We handle building control where the job needs it; see our building regulations page.

Which towns in Hampshire do we cover?

• Southampton
• Portsmouth
• Basingstoke
• Gosport
• Waterlooville
• Farnborough
• Eastleigh
• Winchester
• Havant
• Andover
• Fareham
• Aldershot
• Fleet
• Totton
• New Milton
• Bordon
• Hythe
• Yateley
• Alton
• Emsworth
• Hedge End
• Romsey
• Hayling Island
• Tadley

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