Socio and Bio-Physical Benefits

Below you will find brief descriptions of the various socio and bio-physical benefits associated with green roofs. The benefits are organized under several categories. You can browse summaries by clicking on any benefit category to get a list of the summaries that pertain to that category. If you want to see only those summaries that pertain to a particular benefit, click on the specific benefit name. If you want to see all the summaries that relate to Socio and Bio-Physical Benefits click here.

Materials

Reduction in drain size - Due to the reduced quantity of storm water run-off, smaller roof drains may be possible.
Increased membrane life expectancy – Because it shields a roof assembly from drastic temperature changes and ultra violet rays, a green roof can double the life expectancy of a waterproofing membrane.
Reduction in use of potable water – Storm water can be collected on the roof and used to irrigate the vegetated areas, reducing the use of potable water for this purpose.

Energy Use

Increased solar efficiency - By reducing ambient temperatures, green roofs can increase the efficiency of electricity production in solar panels.
Reduction in energy used for air conditioning – By insulating buildings against heat gain in the warm months and reducing the ambient air temperature at rooftop air intake vents, green roofs can reduce energy use from air conditioning.
Reduction in energy used for heating– In the cold months, the insulating effect of green roofs can help reduce energy used for heating.
Reduce greenhouse gas emissions from energy production – Green roof technology reduces the energy used in heating and cooling a building by providing additional thermal insulation. The reduced demand on power plants will decrease the amount of greenhouse gases being produced and the release of other polluting byproducts into the air.

Fire Retardation

Fire Retardation – The vegetation and humidity in the growing medium on green roofs burns more slowly than the materials in a conventional roof.

Blocking radiation from telecommunications

Blocking radiation from telecommunications – Electromagnetic radiation penetrating into buildings from above can be virtually eliminated by a green roof. This may be of particular interest in buildings with telecommunication equipment located on the roof.

Aesthetics and well-being

Noise reduction – Green roofs offer excellent noise attenuation, especially for low frequency sounds. An extensive green roof can reduce sound by 40 decibels, while an intensive one can reduce sound by 46-50 decibels.
Reduction/mitigation of roof glare – Green roofs can reduce or mitigate glare as compared to reflective roofing systems.

Stress reduction – Studies show that leisure activities in natural settings, such as gardens and parks, are important for helping people cope with stress.
Increased productivity – The availability of a natural view in places of employment decreases job stress, ailments, and headaches. These factors contribute to increased job satisfaction and employee productivity.
Reduction of sick days – The availability of a natural view in places of employment decreases job stress, ailments, and headaches. The number of sick days taken by employees can be reduced by access to or a view of green spaces.

Decreased patient healing times – Given that many hospitals are located in highly developed areas, green roofs are a good way to expose patients to nature and improve the healing process. A study that compared post-operative recovery rates for patients with a natural view to those without found that the former made quicker recoveries, had fewer negative evaluations from nurses, and lower rates of medication than those without.

Social

Food security – Given that at-grade land in urban centres is considered far too scarce for community gardens and food production, roofs are a logical location for urban agriculture. Urban food production reduces the uncertainty associated with long-distance food supply, including supply interruptions.

Decreased expenditure on food – Rooftop community gardens can help meet nutritional requirements and reduce household expenditures on food.
Social cohesion – Green roofs that are accessible create meeting places and activity areas that can increase social interaction and community cohesion.
Recreation – Some green roofs are specifically designed for active recreation (e.g., playgrounds) or leisurely activities (e.g. relaxing beside a water garden).
Horticultural therapy – Rooftop gardens can serve as a therapeutic tool for physical and mental rehabilitation (e.g., in hospital or nursing home settings).
Job creation – Green roofs draw upon many disciplines for their design and installation. As the demand for this technology increases, so will the demand for green roof professionals, such as suppliers and manufacturers of green roof components, installers, and landscapers.

Storm water management

Improved storm water run-off quality – Studies have shown that a traditional roof’s runoff contains high concentrations of pollutants from rainwater, roofing materials, and atmospheric deposition. The plants and growing media used in green roofs help decontaminate run-off, loading fewer pollutants into the municipal storm water system.
Reduced storm water run-off quantity –Storm water and sewage systems involve high capital investment into the components, continual maintenance and inspection. By capturing and temporarily storing storm water, green roofs can reduce run-off volumes.
Extend lifetime of infrastructure – By increasing stormwater retention, green roofs can reduce the need to expand or rebuild related infrastructure.
Reduction in combined sewer overflow (CSO) events – Many older cities have combined sanitary and storm sewers, whose treatment capacity can be overwhelmed by heavy precipitation. By reducing runoff, green roofs can limit the occurrence of CSO events and thereby diminish the quantity of untreated wastewater entering fresh water bodies.
Reduction in incidence of flooding – By reducing peak flows during storm events, green roofs can reduce the incidence of flooding..

Temperature Regulation

Reduce ambient temperature – The reintroduction of vegetation into cities promotes natural cooling through photosynthesis and evapotranspiration. These processes contribute significantly to the reduction of ambient temperature in densely packed urban environments.

Mitigate the urban heat island (UHI) effect – Green roofs contribute to the mitigation of the UHI effect by covering some of the hottest surfaces in the urban environment – rooftops. Traditional black roofs can reach temperatures of 158°F/ 70°C and as a result have an enormous effect on building and ground level temperatures. One study found that 25% green roof coverage can reduce the UHI by up to 1.8°F/1°C.

Air Quality

Reduction in airborne pollutants – High levels of air born pollutants resulting from automobile and industrial plant emissions have been directly correlated with poor respiratory health and premature death. Green roofs mitigate air pollution levels by lowering extreme summer temperatures, trapping particulates, and capturing gases.

Biodiversity

Creation of habitat – Ecosystems are rapidly being consumed by suburban development, adversely affecting the diversity of plant and wildlife in North America. Green roofs are a unique opportunity to recreate destroyed habitats for native flora and fauna through careful design.