the benefits of green roofs

The benefits of installing a green roof are numerous and wide ranging. Social, economic and environmental benefits can contribute positively to issues surrounding climate change, flooding, biodiversity and declining green space in urban areas. The introduction of a green roof improves not only the building space in which you live but benefits those around you aswell.

  • The Benefits Of Green Roofs

Ecological refuges

Green roofs offer rare undisturbed habitat for wildlife. We can customise and design living roofs to target key, often protected, species in line with Biodiversity Action Plans (BAPs), Ecologists’ specifications and local initiatives. For example, we have designed and installed green roofs within London specifically designed for stag beetles Lucanus cervus in line with the 2012 London BAP.

  • Bee on Sedum

Aid to planning & BREEAM

Planning officers often specify green roofs as a condition of planning permission. They do this for a variety of reasons, from ensuring that a development blends with the landscape (as with the rolling hills of the Cotswolds on the Kanes Food Roof), to meeting specific local initiatives. We have a lot of experience working with planning officers in meeting project specific requirements.

Green roofs can also gain credits with BREEAM (Building Research Establishment Environmental Assessment Method), particularly within the land use and ecology sections. We have a highly adept technical team who can work with BREEAM assessors and Ecologists on your behalf in order to attain the necessary BREEAM credits.

To read more about BREEAM

  • living roof planning

Storm water management

Flooding is a serious problem in the UK. Impervious surfaces such as slate, concrete or waterproof membranes direct rainwater rapidly into drains, causing a surge in water flow which our Victorian sewer systems struggle to cope with. Combined Sewerage Overflows (CSOs) are used when sewers become overloaded and in danger of flooding. In London, there are 57 CSOs which discharge around 39 million tonnes of untreated sewage annually into the Thames. Compared with traditional roofs, green roofs reduce the volume of rainwater run-off, and attenuate the flow (see hydrograph). This reduces the stress on our antiquated sewers, and helps to prevent discharges & floods occurring.

A great video explanation can be seen at:

  • Storm water management

Reduction of the Urban Heat Island (UHI) effect

Dense urban areas are often 2 to 3 degrees centigrade warmer than the countryside that surrounds them. This is caused by materials which retain heat, such as tarmac, and processes which produce it as a bi-product, such as cars. Urban Heat Islands (UHIs) disrupt local climatic cycles, particularly the hydrological cycle. This stresses the local ecosystem and is detrimental to wildlife.

Traditional roofs experience extreme flux of surface temperature over a 24 hour period & fuel the UHI effect. Living roofs help to mitigate UHIs by regulating the surface temperature through absorption of sunlight. Reduction of temperature extremes also reduces the stresses on the waterproofing layer and extends their lifespan.

Image taken from:

  • Urban Heat Island Effect

Noise Reduction

Living roofs are absorptive of sound, and have two main acoustic benefits:

  • Reduction of sound penetration to the building within.
  • Mitigation of sound propagation across the roofs surface.

Sound waves are absorbed, reflected or deflected. The growing medium tends to block lower sound frequencies whilst the plants block higher frequencies. The amount of sound insulation is dependent on the system used and the substrate depth. A standard sedum blanket green roof can reduce sound by 8dB compared with a conventional roof system. This could be particularly important in areas of high noise pollution such as the approaches to airports.

Pollutant Filter for Air and Water

Particulate pollutants often come to rest on roofs, and therefore become dissolved within any run-off from said surface. Green roofs filter any run-off therefore capturing the pollutants and improving the water quality.

Living roofs can help to improve the water quality run off, in comparison to a 'standard' roof  through the absorption of atmospheric pollutants (heavy metals and volatile organic compounds) in to the living roof system.

Air quality is also improved through the capture of airborne pollutants. Specifically carbon dioxide through photosynthesis, which is the process by which plants turn carbon dioxide in to oxygen and food through the use of energy from the sun light and water. Carbon dioxide has been strongly linked to being the main driver of climate change

  • Green Roof On Bus

Amenity Space

Living roof areas can add a great deal of value to building. With space at a premium in modern cities, turning an otherwise unused area can not only add an area of relaxation for the buildings users but add value for the buildings owners.

  • Deck Chairs