Calne at a glance
- Postcode districts
- SN11
- Population
- about 17,274 (GeoNames)
- Council area
- Wiltshire Council
- Building approval
- Wiltshire Council building control, or a registered building control approver
- Nearest main town
- Swindon, about 13 miles
- Guide price region
- South West (+3% on West Midlands rates)
Why upgrade to a warm roof in Calne?
Landlords with flats and HMOs in Calne sometimes hear from tenants about cold top-floor rooms and black mould on ceilings. A warm roof upgrade during re-roofing tackles both the heat loss and the condensation behind the mould, and helps keep the roof timbers dry.
Calne's flat roofs are mostly on bungalows with flat-roofed side extensions and dormers, with plenty on shops with flat-roofed rear stores below flats too. The South West averages roughly 1,260 mm of rain a year and many roofs face wind off the Atlantic, so we specify fixings and edge details for wind uplift as well as drainage.
How much does a warm roof upgrade cost in Calne?
Guide price in Calne: £2,900–£5,050 for a 20 m² extension roof in EPDM with a new deck and insulation, including VAT at South West rates. 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 | £2,900–£5,050 |
| Extension (20 m²), EPDM with sedum green roof | £4,550–£8,350 |
Can a cold flat roof be converted to a warm roof?
Yes, and it is the usual approach when an older cold roof is re-covered. The old covering is stripped, the deck is checked and replaced where needed, and the vapour control layer, insulation and new waterproofing go on top.
The existing insulation between the joists is assessed at the same time. Leaving it in place can create a cold, unventilated gap that traps moisture, so it is often removed or the build-up is designed so that most of the insulation sits above the deck. We decide this case by case once we can see inside the roof. If the covering is still sound and you are only patching it, the upgrade isn't usually required, and our repair or replace guide explains how to decide between the two.
What's included?
- Vapour control layer on the warm side of the insulation
- Survey of the deck, joists and existing insulation
- Rigid insulation boards sized to the U-value target
- Building control or building standards handled where needed
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?
Warm roof insulation upgrades in Calne: questions
Do you cover Calne?
Yes. Calne is part of our Wiltshire coverage, including postcode districts SN11. 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 Calne?
Where the work needs approval it goes to Wiltshire 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 warm roof upgrade cost in Calne?
£2,900–£5,050 for a 20 m² extension roof in EPDM with a new deck and insulation, at South West guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Is a warm roof worth it on a garage?
On a detached, unheated garage, usually not, as there is no heated space to protect and the thermal rules don't normally apply. On an integral or heated garage, or one being converted into a room, it is.
Is there VAT relief on flat roof insulation?
Don't count on it. Insulation fitted as part of a roof replacement is usually treated as part of a single standard-rated job. Check your own case with HMRC guidance or an adviser.