Greening Our Rooftops


Credit: 925 Bergen St, Brooklyn | © Big Sue LLC

Last week, the City Council passed three laws that will make New York City rooftops greener places. This brings the total number of NYC Green Codes Task Force recommendations that have been implemented by the Council to 16. Until the Mayor signs the legislation, they won’t be assigned a Local Law number so I’ll refer to them by their “Introduction” or bill number.

Two of these laws are about old regulations getting out of the way of green building. Introduction 341 implements Task Force recommendation Energy Fundamentals 14, Allow Large Solar Rooftop Installations. And Introduction 358 applies the approach to combined heat and power. Currently, the Building Code exempts a range of mechanical equipment on rooftops, including HVAC equipment and water tanks from building height restrictions. However, until these two laws were passed, solar and CHP equipment were not included in these exemptions – they are now.

Introduction 341 goes one step further for solar equipment. These same Building Code provisions limit the amount of rooftop that can be covered with mechanical equipment to 1/3 of the roof; otherwise it is counted as another floor of the building. Under the new law, solar equipment is not counted towards these limitations and can cover as much of the roof as permitted by other codes (such as the Fire Code).

The third law, Introduction 347, implements Task Force Proposal Energy Fundamentals 11, Reduce Summer Heat With Cool Roofs. This law updates existing Building Code requirements for reflective roof coatings to better align with LEED and clarifies exceptions to the standard. Under the changes, cool roof coatings will be required for reroofing of existing rooftops, and also for buildings constructed under the 1968 building code and normally exempted from many newer requirements. The law also clarifies that exemptions for green roofs apply to agricultural plantings and adds exemptions for:

*ballasted roofs;
*roofs used as playgrounds;
*areas under mechanical equipment or other rooftop structures;
*portions of roofs covered with decking materials.

You can read a far more detailed explanation of Introductions 347 (cool roofs) and 341 (solar), as well as all implemented NYC Green Codes Task Force recommendations on our web site.

Thanks to the City Council and their staff and the Mayor’s Office for makes these laws happen. Congratulations also to the Energy & Ventilation Committee of NYC Green Codes Task Force, whose recommendations formed the basis for these new laws.

About the author

Russell Unger
Russell Unger is the Chief Strategy Officer at Urban Green Council.