The Green Area Ratio sets environmentally friendly urban planning requirement for D.C. buildings.
By Brittney Dunkins
With the influx of young urbanites, new businesses and booming real estate growth, D.C. has faced an increasingly urgent issue of the 21st century: how to handle rapid growth and engage in environmentally responsible urban planning.
The Green Area Ratio (GAR), a sustainable zoning regulation enacted by the D.C. Office of Planning last month, will tackle this issue, creating minimum standards for sustainable land use and site design within city limits.
The measure is the result of research conducted by George Washington University Assistant Professor of Geography Melissa Keeley, an expert in green infrastructure and urban sustainability. It will require sites to incorporate key sustainable features to reduce storm water runoff, improve air quality and keep the city cooler.
“The GAR is a broad policy that is flexible for developers and designed to account for the multiple benefits of green infrastructure,” Dr. Keeley said. “Private property owners can choose to meet requirements from a toolbox of techniques that will each contribute different levels of environmental benefits.”
Under the GAR, green infrastructure techniques are assigned “weightings” based on a meta-analysis of available science assessing their ability to manage environmental impacts and climate adaptations, including urban heat island amelioration, air quality improvement and storm water mitigation.
Properties throughout the city are also assigned “greening targets” based on land use in order to maintain a minimum standard of green infrastructure. Then, whenever development occurs, owners can integrate sustainable land use practices appropriate to a parcel to achieve the required GAR rating for their particular site.
Green infrastructure refers to vegetation, soils and bioengineered systems that provide ecological services such as microclimate regulation and air quality improvement. These services are designed to provide environmental benefits in urban areas, Dr. Keeley said.
While working in Berlin at the Senate Department for Urban Development and the Environment in 2002 as a fellow of the Robert Bosch Foundation, Dr. Keeley researched policies similar to the GAR.
The first city to adopt such a policy in 1997, Berlin was the perfect place to witness the benefits of the initiative, she said.
“When I saw such an approach in practice in Berlin, I felt that it had potential for adoption and adaptation because it is a straight-forward way to address the pressure U.S. cities currently face to manage storm water and other priorities such as air quality improvement,” she said.
To research green infrastructure and explore the possibility of its adoption in U.S. cities, Dr. Keeley has been awarded fellowships to Harvard as well as Columbia University’s Earth Institute and federal grants from the National Science Foundation, the Environmental Protection Agency and the National Oceanic and Atmospheric Administration.
In 2009, while continuing her research, she introduced the concept and a prototype to stakeholders in Washington, including the EPA, the District Department of the Environment, the D.C. Office of Planning and the Metropolitan Washington Council of Governments.
After conducting independent research, adjusting the prototype and consulting with Dr. Keeley’s research team, the D.C. Zoning Commission adopted the GAR into city ordinances.
“The GAR is a way for the city to ensure environmental performance through the open spaces that are required through zoning,” said Laine Cidlowski, urban sustainability planner in the D.C. Office of Planning. “Since the initial meeting, the concept was submitted to the Zoning Commission for their approval, language for the regulation was passed by the Zoning Commission and the GAR went into effect on Oct. 1.”
Since its implementation in Berlin, the GAR has been adopted in Sweden, South Korea and Seattle, in addition to D.C. Dr. Keeley hopes that more cities will see the benefits of inclusive green infrastructure policies.
“In the U.S., we are at the stage where there have been many successful demonstration projects for a variety of green infrastructure techniques, and now we are preparing to scale-up the usage of these techniques systematically so that they can have positive environmental and social impacts city-wide,” she said.
“It is prudent for us to learn from the experiences of other cities and countries.”