What about other benefits? Do you really know it all?
Let’s check all 3 categories of green roof benefits – environmental, economic and last but not least, social benefits of vegetative roofs…
1. Environmental Benefits of Green Roofs
a. Reduction of Urban Heat Island Effect (UHI)
Green roofs are one of the most effective ways to reduce the ambient air temperature in urban areas. During summer the temperatures in cities are approximately 5-7ºC higher than in the countryside due to buildings and roads heat absorption and the temperature on the traditional roof can be up to 40ºC higher compared to the green roof. According to research carried out by the Tyndall Centre for Climate Change there is a need of 10% moregreenery in towns to mitigate the UHI Effecm
b. Rainwater management
A major advantage of green roofs is the reduction of stormwater runoff, which leads to a decrease of the burden on sewer systems by 70-95% in summer. Green roofs have influence on cost reduction due to low orno need for raincatching cisterns and similar equipment which is usually used for stormwater management. Rainwater retention capability helps to limit accidents caused by heavy rainfalls.
c. Rainwater purification
Through natural bio-filtration, green roofs prevent contaminants and toxins from reaching streams and waterways. According to Kohler & Schmidt research (1990) 95% of the lead, copper and cadmium sulphide and 19% of the zinc coming from the rainwater remains in the substrate, which helps to improve local water quality.
d. CO2 reduction
Green roofs help to reduce the amount of CO2 in the air, which is considered one of the most important causes of global warming. 1m2 of a green roof can absorb 5 kg of CO2 yearly. Additionally, due to reduced energy consumption there is a further impact on carbon dioxide reduction by 3.2kg yearly.* As a perspective, 1m2 of green roof can absorb the same quantity of CO2 as a regular car would emit during a 80km drive.
e. Cleaner air
The plants on green roofs can also capture airborne particles such as smog, heavy metals and volatile organic compounds from the local atmosphere which has a positive effect on air quality and health of inhabitants. Researchers estimate that 1m2 of a green roof can help to absorb 0.2kg of airborne particlesfrom the air every year**.
f. Natural habitat
As urbanisation increases, ensuring biodiversity is one of the key requirements for local councils. Green roofs can provide a habitat for various species and restore the ecological cycle disrupted by urban infrastructure.