Green Roofs

Increasing vegetated footprint, reducing our carbon footprint

Green Roofs are one of my favorite sustainable design amenities. We see it in movies all the time, in modern-new age utopias with big green roofs on every home. Essentially, a green roof is a roof with vegetation or the process of growing plants on rooftops in order to replace the vegetated footprint that was destroyed when the building was constructed. There are basically three times of green roof systems; Intensive, Extensive and a mix of both. Intensive green roofs are roofs that use a wide variety of plant species and may include bigger plants like trees and shrubs, is usually limited to flat roofs, requires more intense maintenance and is most times accessible to the public by some park-like amenity. Extensive green roofs are limited to smaller plants like herbs, grasses, mosses and succulents, not usually accessible to the public and has very little maintenance. From a sustainable design perspective, green roofs have tons of benefits; environmentally, economically and socially. Green roofs are also a strategy within resilient design because they can be used for urban agriculture and for other means that can better prepare and adapt spaces and communities to climate change and/or sudden disruptions.

Environmentally:

• Improve stormwater management by retaining 60-100% of stormwater and thus reducing flooding and sewage system loads.

• Improving water quality through filtration before it enters the ground or bodies of water, can also be irrigated with use of greywater.

• Mitigates Urban Heat Island effects; vegetation provides shade and through evapotranspiration of plants allows for cooler temperatures.

• Reduces air pollution through air purification

• Sequesters carbon, thus reducing greenhouse gas emissions

• Increases urban biodiversity of birds, insects and small animals through creating habitat spaces

• Creates a system of adaptation and preparedness to climate change

• Opportunity to recycle compost

Economically:

• Adds real estate value to buildings up to 7% and marketability

• Energy efficiency: protects roofs from direct sun thus reducing cooling demands in hot seasons and minimizes heat loss and is added insulation during colder seasons reducing heating demands, less energy used, less GHG emissions

• Increases longevity of roofing membrane, minimal need for replacement and reduces material waste from re-roofing

• Creates sustainability and environmental stewardship jobs related to the

Green roof on a building in Hunts Point- a community in the South Bronx plagued by environmental justice and public health issues

green economy

• Natural fire-resistant roof layer

Socially:

• Reduces noise pollution

• Opportunity for urban agriculture and food security

• Adds aesthetics/beauty to site- BIOPHILIA !

• Protects against ultraviolet radiation and creates more pleasant microclimates

• Increases well-being, reduces stress and promotes feelings of relaxation

Green roofs are also called Vegetated Roofs, Eco-roofs and Living roofs.