Gloucester at a glance
- Postcode districts
- GL1, GL2, GL4
- Population
- about 132,416 (GeoNames)
- Council area
- Gloucester City Council
- Building approval
- Gloucester City Council building control, or a registered building control approver
- Guide price region
- South West (+3% on West Midlands rates)
Why upgrade to a warm roof in Gloucester?
Small commercial buildings in Gloucester with large flat roofs can lose a lot of heat through them. Where the roof is being replaced, upgrading the insulation at the same time is required in most cases and helps reduce running costs for the occupier.
Gloucester's flat roofs are mostly on newer estates where the first extension roofs are now being replaced, with plenty on lock-up garage blocks on estates 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 Gloucester?
Guide price in Gloucester: £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 |
Will insulating the roof raise its height, and what about doors and upstands?
Yes. A warm roof makes the roof thicker, often by more than 100 mm depending on the insulation and the U-value target. That extra height is the main thing we plan around.
Waterproofing at a wall usually needs to rise about 150 mm above the finished roof surface, so if the roof gets higher, the upstand has to go higher too. That can be a problem where the roof meets a door threshold, a low window sill, a cavity tray or a rooflight kerb. At the edges, trims and fascias are reset to the new level, and gutters may need to move.
Where there isn't enough height, the options include using thinner, higher-performance insulation, lowering the deck where the structure allows, raising the sill or threshold, or, where it is genuinely not feasible to reach the full target, insulating as far as is reasonable and recording why with building control. We work this out at the survey so there are no surprises on the day.
What's included?
- Rigid insulation boards sized to the U-value target
- Vapour control layer on the warm side of the insulation
- Survey of the deck, joists and existing insulation
- New waterproofing, with 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?
- Cheltenham · 7 mi
- Stroud · 8 mi
- Tewkesbury · 9 mi
- Cirencester · 15 mi
- Great Malvern · 17 mi
- Evesham · 20 mi
Warm roof insulation upgrades in Gloucester: questions
Do you cover Gloucester?
Yes. Gloucester is part of our Gloucestershire coverage, including postcode districts GL1, GL2, GL4. 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 Gloucester?
Where the work needs approval it goes to Gloucester City 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 Gloucester?
£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.
Will a warm roof make my room warmer?
Usually, yes. A room under a poorly insulated flat roof loses less heat once the roof is upgraded and tends to feel more even in temperature. How much difference you notice depends on how the roof was built before.
How thick does flat roof insulation need to be?
It depends on the insulation product and the U-value target. With common PIR boards, meeting a renovation target usually means well over 100 mm. Thinner, higher-performance boards are available where height is tight.