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Green and sedum roofs in York

A sedum roof suits an extension in York that is overlooked from upstairs windows, or a garden building you want to blend into the garden. We explain the weight, planning and maintenance points at the survey so the decision is a clear one.

Sedum green roof with a gravel border and inspection chamber on a single-storey extensionComputer-generated example image

York at a glance

Postcode districts
YO1, YO10, YO19, YO23, YO24, YO26, YO30, YO31 and 1 more
Population
about 156,135 (GeoNames)
Council area
City of York Council
Building approval
City of York Council building control, or a registered building control approver
Guide price region
Yorkshire and the Humber (−5% on West Midlands rates)

Why choose a green roof in York?

Rainwater from flat roofs in York runs off quickly in heavy showers. A green roof holds some of that water back and releases it more slowly, which is one reason some owners and developers choose one. The flowering sedum also draws in bees and other insects.

In a city like York, flat roofs are commonly found on 1960s and 1970s link-detached houses with flat-roofed garages and porches or shops with flat-roofed rear stores below flats. England averages roughly 870 mm of rain a year; the Pennine side of Yorkshire is wetter and windier than the east, so we specify for the site rather than the county.

How much does a green roof cost in York?

For York we use Yorkshire and the Humber rates: £4,200–£7,700 is the guide for a 20 m² insulated extension roof finished as a sedum green roof, VAT included. The fixed price comes after a free survey for new and replacement roofs.

JobGuide price inc VAT
Extension (20 m²), EPDM with sedum green roof£4,200–£7,700
Extension (20 m²), EPDM, new deck + insulation£2,650–£4,650

How long does a green roof last and how much maintenance does it need?

A well-built extensive green roof needs one or two maintenance visits a year, and the plant layer can help protect the membrane from sunlight and temperature swings.

Typical maintenance means pulling out weeds and tree seedlings before they root, clearing outlets and the gravel strips around edges, filling in any bare patches, and adding a slow-release feed if the sedum looks thin. Sedum is drought-tolerant once established, but newly laid blankets may need watering in a long dry spell during the first season.

The waterproofing underneath has the same expected life as on any other roof of that system. A green roof also slows down rainwater run-off from the roof and, when sedum flowers, attracts bees and other insects. Some councils encourage green roofs for those reasons, so it is worth mentioning one in a planning application for a new extension. Our maintenance guide covers routine checks.

What's included?

  • Warm or inverted build-up to suit the roof
  • Drainage layer, filter and lightweight growing medium
  • Pre-grown sedum blankets laid and watered in
  • 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?

Green and sedum roofs in York: questions

Do you cover York?

Yes. York is part of our North Yorkshire coverage, including postcode districts YO1, YO10, YO19, YO23, YO24, YO26 and 3 more. 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 York?

Where the work needs approval it goes to City of York 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 York?

£4,200–£7,700 for a 20 m² insulated extension roof finished as a sedum green roof, at Yorkshire and the Humber guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.

Do I need to water a sedum roof?

Usually only in the first season, during long dry spells, while the blankets establish. After that, sedum copes with dry weather well.

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.

Other flat roof work in York

Green and sedum roofs in York: get a fixed price

Free survey and a written fixed quote for replacement and new roofs. No obligation.

Call usGet a guide price