Out of sight and out of mind for most city-dwellers, roof tops comprise one third of a city’s total horizontal surface area. Roof gardens like Fenway Farms are making these forgotten spaces the front line for solving some of Boston’s urban environmental problems.
Fenway Park’s green roof uses the natural capacities of plants and soil to sequester carbon, reduce air pollution, and increase local biodiversity and wildlife populations. In addition, its 10-inch deep layer of soil can reduce stormwater runoff by up to 80% and improve water quality.
Fenway Farms grows various types of produce on top of Fenway Park. Green Roofs.
Green roofs also have positive implications for energy use. Acting as an additional layer of insulation, roof gardens keep buildings warmer in winter and cooler in summer, and can contribute to a reduction of city temperatures by weakening the urban heat island effect. In addition, roof gardens hold a lot of potential for urban agriculture. In fact, Fenway’s basketball court-sized garden produces a whopping 4,000 pounds of vegetables for the park and local community each year. Proactively using roof spaces for food production could help provide relief for metro area residents who are food insecure.
If Boston is going to be a green, sustainable city, maximizing the positive contributions of its roof tops should be a top priority. To achieve this end, we must come together and demand that Boston enact legislation that mandates the creation of green roofs on all new construction projects.
Boston is not be the first city to consider such legislation. In 2009, Toronto passed a municipal bylaw requiring roof gardens on all new construction. France and San Francisco followed suit with their own green infrastructure requirements in 2015 and 2016, respectively.
Luckily, Boston city government is already familiar with the benefits of green roofs. In 2009, the mayor’s office undertook a comprehensive study of optimal green roof design for the Boston climate, and even built a 400-square-foot demonstration roof garden on top of City Hall. Yet, a comparison of that garden to the 35,000-square-foot green roof on Toronto City Hall clearly shows that Boston is lagging behind other sustainable cities.
Toronto City Hall’s public roof garden. Toronto Star.
The main hurdle to scaling up green roofs is their construction and maintenance costs. An extensive garden, with simple grass-like vegetation and a thin layer of soil can cost $10-50 per square foot, while an intensive garden that supports large vegetation and a deep layer of soil can cost up to $200 per square foot and tends to have greater irrigation needs. Of course, these initial upfront costs can have their payoffs: the intensive gardens tend to be most effective in stormwater mitigation and building insulation.
If Boston is going to mandate a green roof requirement — and they should — fairness dictates that they also provide incentives to make it easier for those trying to comply. Incentives will also help to ensure the success of Boston’s green roof program in the same way that similar incentives stimulated the growth of solar technology. In fact, back in 2009 Boston City Council considered a green roof subsidy based on New York City’s existing program, which provided a $5 per square foot rebate up to $100,000 per project; however, the proposal did not pass. Now in 2016, this incentive program is long overdue.
It is clear that action needs to be taken by our city government to make green roofs an integral part of our city. We must act now.
What YOU Can Do:
- Contact Your Representatives
Call or send an email to Boston City Council and tell them you want to see green roofs on new construction projects and existing buildings, and that you support financial incentives for green roof projects.
- Get Involved
Organizations around the city are teaching people how nature-inspired solutions, like green roofs, can solve modern day problems. Reach out to groups like Green City Growers and Biomimicry New England to help out with a green infrastructure project in your community.
As Mayor Menino once said, “today, more than ever, we have to be creative and innovative when it comes to environmental issues and energy efficiency.” Requirements and financial incentives for green roofs will encourage the rapid and innovative change necessary to help transform the City of Boston into a model sustainable city. A municipal bylaw requiring green roofs on new buildings, paired with financial support, is the push that designers need to begin thinking of ecosystem benefits as an essential goal in their designs, and community engagement and political participation is can make this change happen.