Daventry at a glance
- Postcode districts
- NN11
- Population
- about 28,123 (GeoNames)
- Council area
- West Northamptonshire Council
- Building approval
- West Northamptonshire Council building control, or a registered building control approver
- Nearest main town
- Rugby, about 9 miles
- Guide price region
- East Midlands (−2% on West Midlands rates)
Why choose a green roof in Daventry?
Small commercial buildings and blocks in Daventry with a flat roof sometimes add an extensive green roof as part of a refurbishment. The structural check and safe access for maintenance matter even more on these larger roofs, which may need edge protection or fall-arrest points for each visit.
Around Daventry, flat roofs are common on bungalows with flat-roofed side extensions and dormers and on low-rise post-war blocks of flats. The East Midlands is drier than the west of Britain, so most flat roofs here fail through age, UV and poor detailing at upstands rather than sheer rainfall.
How much does a green roof cost in Daventry?
Guide price in Daventry: £4,300–£7,900 for a 20 m² insulated extension roof finished as a sedum green roof, including VAT at East Midlands rates. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Extension (20 m²), EPDM with sedum green roof | £4,300–£7,900 |
| Extension (20 m²), EPDM, new deck + insulation | £2,750–£4,800 |
Can my flat roof take the weight of a green roof?
Not every roof can, which is why we check the structure before quoting. A sedum roof is light compared with an intensive garden, but its growing medium holds water, and a saturated build-up adds significant weight to the roof.
We look at the joist sizes, spans and spacing, the condition of the deck and what the roof sits on. On a recently built extension with generously sized joists, an extensive green roof may be straightforward. On an older garage or a roof with undersized or rotten timbers, the structure may need strengthening, or a structural engineer's calculation may be needed before we can go ahead.
In England, a new roof covering that adds 15% or more to the weight of the roof triggers building control approval, and a green roof will often fall into that category. We handle building control where it is needed. The building regulations page covers the approval routes in each nation.
What's included?
- Gravel strips kept clear around edges and outlets
- Warm or inverted build-up to suit the roof
- Drainage layer, filter and lightweight growing medium
- Structural check of joists, deck and supports
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?
- Rugby · 9 mi
- Northampton · 12 mi
- Royal Leamington Spa · 15 mi
- Banbury · 15 mi
- Warwick · 18 mi
- Coventry · 18 mi
Green and sedum roofs in Daventry: questions
Do you cover Daventry?
Yes. Daventry is part of our Northamptonshire coverage, including postcode districts NN11. 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 Daventry?
Where the work needs approval it goes to West Northamptonshire 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 green roof cost in Daventry?
£4,300–£7,900 for a 20 m² insulated extension roof finished as a sedum green roof, at East Midlands guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Does a green roof leak more than a normal flat roof?
No, as long as it is built correctly. The waterproofing beneath is what keeps water out, and the green layers protect it from sun and weather. The main risk is building it on a weak or ageing membrane.
Can you put a green roof on a pitched roof?
We install green roofs on flat roofs only. Sloping green roofs need extra restraint to stop the growing medium slipping, and they are a specialist job outside our work.