Alerts and Updates

New York City's Sustainable Roof Laws Likely to Increase Construction Costs

December 19, 2019

Projects that include a sustainable roofing zone may be able to obtain a New York state property tax abatement.

As of November 15, 2019, building owners in New York City are required to install “sustainable roofing zones” on all newly constructed buildings, expansions of existing roofs and roof replacements. The new laws were passed by the New York City Council on April 18, 2019, and became law on May 20, 2019. These new ordinances, known as Local Laws 92 and 94 of 2019, passed as part of a broad package of laws known as the New York City Climate Mobilization Act, whose goal is reduction of building carbon emissions. Because the sustainable roof requirements are effective now, plans submitted to the Department of Buildings for approval must include plans for sustainable roofs.

Local Law 94 amends the New York City Building Code and defines a sustainable roofing zone as an area of a roof assembly where a solar photovoltaic power generation system, a green roof or a combination of the two is installed. A roof assembly is a system designed to provide weather protection and resistance to design loads, and consists of a roof covering and roof deck or a single component serving as both roof covering and roof deck. A roof assembly includes the roof deck, substrate or other thermal barrier, insulation, vapor retarder and roof covering. “Roof deck” is the structural surface to which the roofing and waterproofing system is applied.

New roofs for all types of buildings must each have a sustainable roof zone. For residential buildings, the requirement applies if the contiguous roof zone on a roof is 100 square feet or greater, and for other buildings, if the contiguous roof zone is 200 feet or greater. If the contiguous roof space is smaller, but a solar photovoltaic system that can meet or exceed a 4 killowatt capacity can be installed, it must be installed. The minimum solar panel efficiency must be at least 15 percent. If such a solar system cannot be installed, a green roof is required.

In determining the size of the sustainable roof zone, the following areas are excluded from the calculation:

  1. Setbacks, set-asides or access required by the NYC Fire Code, Construction Codes or Zoning Resolution.
  2. Areas occupied by rooftop structures, water towers, greenhouses, mechanical equipment, towers, antennas, parapets, guardrails, equipment access pathways, etc.
  3. Areas occupied by obstructions related to stormwater management practices, including but not limited to cisterns, or reuse systems installed to comply with permits issued by the Department of Environmental Protection.
  4. Building setbacks, including terraces that are noncompliant pursuant to NYC Zoning Resolution, or that are voluntarily provided. Each must comprise less than 25 percent of the largest floor plate of the building.
  5. Recreational spaces integral to the principal use of the building, including but not limited to playgrounds and participant sports arenas for sports facilities and schools or other areas documented on the certificate of occupancy or Department of Buildings approved filing.
  6. Pitched roofs with slopes greater than 17 percent that would accommodate less than 4 killowatts of solar photovoltaic generating capacity. Supporting documents must be submitted.
  7. Areas where the Department of Buildings determines that site conditions are unfavorable for either solar photovoltaic generation or a green roof system, for example, where the building structure cannot support the added weight.

When preparing to construct a new project that requires installation of a solar photovoltaic generating system or a green roof, applicants must provide roof plans with a code compliant roofing zone, with both the included and excluded areas. The anticipated generation, if any, must be provided in a statement by a qualified contractor or New York state registered design professional.

Projects that include a sustainable roofing zone may be able to obtain a New York state property tax abatement. Affordable housing may have until November 2024 to comply.

It is unclear whether a building owner must own the solar photovoltaic generation plant if installed or whether it can either lease the equipment or purchase the electricity pursuant to a power purchase agreement from a project developed and owned by a third party. The law is vague in other places as well, including whether the owner has an obligation to replace a rooftop solar plant at the end of its useful life or if it can be replaced with a green roof.

The requirement to design buildings with sustainable roofs, whether owned by the building owner or others, will almost certainly increase the cost of building a new building or replacing a roof. While the new requirements for building sustainable roofs should reduce emissions in New York City and reduce energy costs for the building, whether such cost reductions will offset additional costs of construction remains to be seen.

For Further Information

If you have any questions about this Alert, please contact Kenneth H. Lazaruk, Phyllis J. Kessler, Jon C. Popin, any of the attorneys in the Energy Industry Groupattorneys in the Construction Group, attorneys in the Real Estate Practice Group or the attorney in the firm with whom you are regularly in contact.

Disclaimer: This Alert has been prepared and published for informational purposes only and is not offered, nor should be construed, as legal advice. For more information, please see the firm's full disclaimer.