Zoning Goes Green

Howard Slatkin
Director of Sustainability and Deputy Director for Strategic Planning
New York City Department of City Planning

Note: This blog was originally published on Urban Green Council blog.

Any building in New York City should be allowed to generate solar energy on its rooftop. Buildings should be rewarded, not penalized, for adding insulation to reduce their energy use and carbon emissions. It’s a great addition to the urban landscape when green roofs and urban farms sprout on top of our buildings.

No-brainers, right? Well, until yesterday, New York City’s zoning inadvertently discouraged or prevented all these green building strategies. But now, our zoning has gone green.

At the Department of City Planning, we learned from building owners, developers, architects, and engineers that zoning regulations written in the mid-20th century were preventing our buildings from joining us in the 21st century. Buildings could add air conditioning equipment on their rooftops, but not photovoltaic panels to generate clean, renewable energy, or the planting bed for a green roof. An old-fashioned awning could be used to shade a window, but modern sun control devices couldn’t hang over a yard. Adding continuous external insulation to dramatically improve energy efficiency could push a building over limits on floor area.

So the Department, under the leadership of Commissioner Amanda Burden, embarked upon the most comprehensive effort in any U.S. city to sweep aside zoning impediments to green buildings. The product of this effort, the Zone Green text amendment, was approved yesterday by the City Council. Developers and building owners now have more choices for the investments they can make to save energy, save money and improve the quality of our environment.

Before Zone Green, developers were confronted with a tradeoff between thicker, energy-efficient walls and usable interior space, because floor area was always measured to the outer edge of the exterior wall. Now, new buildings that exceed the requirements of the New York City Energy Conservation Code can deduct a portion of the thickness of exterior walls from floor area, leveling the playing field for highly energy-efficient construction.

The zoning changes promote not only new green buildings, but also retrofits of existing buildings. Existing buildings can add up to eight inches of wall thickness for the purposes of external insulation, without violating limitations on floor area or requirements for yards or other open areas. Features like solar panels, recreational decks, and sun control devices can be added to new or existing buildings. Complete information about the zoning changes is available on DCP’s website.

Additional legislation at the City and State level will extend the reach and effectiveness of Zone Green. On Monday, the Council also approved legislation enabling sun control devices to project over streets and sidewalks to the same 2-foot-6-inch dimension permitted for these devices within the property line under the zoning. In addition, the State Senate has approved legislation that would modify the Multiple Dwelling Law to enable pre-1961 buildings to make use of the external insulation allowances of Zone Green, and a companion bill has been introduced in the Assembly.

Thanks are due to Urban Green Council and members of the Green Codes Task Force, whose expertise and support have been indispensable to the Zone Green project from its early development through public review. This collaborative effort will yield benefits for years to come, helping make New York a greener, healthier city.

For more details on Zone Green, hear Howard Slatkin speak on June 12th.

For another blog on this subject, see: "Tapping the Zoning Code for Greener Buildings and Communities"