5. Stormwater Management
Thailand is a prime example of a country that faces frequent flooding and could benefit from the stormwater management provided by rooftop farms.
According to World Bank estimates, nearly 40 percent of Bangkok may become flooded each year by 2030 due to more intense rainfall. Thammasat University’s 7,000-square-meter rooftop farm in Bangkok, helps better manage this excess stormwater.
6. Compliance with Local Laws and Regulations
New York City’s Climate Mobilization Act, passed in 2019, is a good reason building owners, architects and developers have for integrating urban agriculture into their developments. The two laws require green roofs or solar panels on all new construction and significant roof renovations for existing buildings. Learn more about mandates for green roofs in “How to Accelerate Adoption of Rooftop Farming in North America”, below.
7. Eligibility for LEED Credits
Rooftop farms enable buildings to be eligible for LEED credits, a green building rating system developed by the Washington, D.C.-based U.S. Green Building Council. According to USGBC, having a LEED-certified building gives building owners a competitive advantage, attracts tenants and helps manage building performance, among other things. Buildings with a rooftop farm are eligible for up to six LEED credits in the following categories:
- Local Food Protection (1 credit)
- Social Equity within the Community (1 credit)
- Heat Island Reduction (2 credits)
- Site Development: Protect or Restore Habitat (2 credits)
8. Building a Habitat for Pollinators
Green roofs help restore biodiversity to urban areas by attracting pollinators that have been pushed out of the city as their natural habitats get paved over. Brooklyn Grange’s rooftop farm in New York City boasts rooftop beehives. This allows the 5.6-acre farm to grow vegetables and sell honey to local restaurants and markets.
Increased biodiversity can additionally help improve the health of entire cities because biodiversity is an indicator of clean air and waterways.
9. Combining Solar Panels with Green Roofs
Although not commonly assumed, combining solar panels and green roofs can make each component work better. While solar panels can provide shade for plants, reducing the need for watering, the rooftop farm helps lower the temperature of the panels, helping them work better.
The Javits Center’s rooftop farm sports more than 3,000 solar panels, making it the largest solar farm in Manhattan. This piece of green infrastructure produces 1.4 megawatts of solar energy for the building. According to New York’s governor’s office, this number has been “estimated to offset more than 1.3 million pounds of carbon emissions each year”. Learn more about the Javits Center’s rooftop farm’s benefits.
10. Community Development and Wellbeing
Rooftop farms have long been known to provide psychological benefits. Urban green spaces provide sanctuary to plants, insects and people. This additionally aids community engagement and development.
Altius Farms in Denver, a company that builds rooftop farms with tower gardens, employs returning vets as part of its community-minded mission of supplying fresh, healthy produce through a community-supported agriculture harvest subscription program. Through this means, Altius Farms representatives are able to educate their community about nutrition and provide local, wholesome produce for all its constituents.
The Boston Medical Center has a 2,658-square-foot rooftop farm that similarly provides fresh, local produce to hospitalized patients to increase overall wellbeing.
As our climate continues to change and our cities rapidly develop, rooftop farms will provide our communities with a place of refuge. The access to fresh produce, cooler environments and greener landscapes will benefit us all in the seasons to come.
How to Accelerate Adoption of Rooftop Farming in North America
To accelerate the use of underutilized rooftops as rooftop farms, cities need to provide more data and guidance about zoning and best practices for rooftop gardens and farms. Currently only 25 cities in North America have programs or incentives to encourage green roof development—whether for food production, energy production or community engagement.
In January 2017, San Francisco’s Better Roofs Ordinance was the first U.S. city mandate for solar and living roofs on between 15 to 30 percent of roof space on most new construction. By being first, San Francisco has encouraged other cities to similarly take on the challenge of repurposing their empty gray rooftops.
New York City passed two laws in November 2019, known informally as the Sustainable Roof Laws, to require most new buildings to include a sustainable roofing zone on 100 percent of their available roof space. Denver has also generated a green roof ordinance to limit atmospheric air pollution and reduce urban heat island effects. Meanwhile, Portland, Ore., has an eco-roof requirement, mandating vegetation to cover 100 percent of the roofs on new buildings with a net building area of 20,000 square feet.
If you are seeking to implement a rooftop farm or green roof on your next project, be sure to contact your city’s department of planning to see what requirements and incentives the city offers. If you need further assistance, visit www.greenroofs.com and www.agritecture.com.
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