New York City’s Local Laws 92 and 94, part of the Climate Mobilization Act, took effect Nov. 15 and require that all newly constructed buildings and all buildings undergoing a complete roof replacement must have a “sustainable roofing zone” covering the entire roof surface, according to www.habitatmag.com.
A “sustainable roofing zone” is defined as a solar photovoltaic electricity-generating system, green roof system or a combination of both. Co-op and condo boards replacing their roof membranes or patching their roofs will be exempt from the laws.
“Everyone’s hair was on fire when the laws were first announced,” says Christa Waring, a principal at CTA Architects who sits on the Building Code Review Committee, which advises the Department of Buildings. “But if you have a concrete roof deck, the chance of having to replace it are slim. If you have a wooden roof deck, the laws will apply only if you have to replace all of the plywood sheeting or the supporting joists.”
Although the requirements for solar panels and the various exemptions are spelled out in the new laws, there is some confusion regarding what constitutes a green roof.
“The green roof must meet the requirements of the Building Code, Section 1507.16, which sets forth nationally recognized standards for green roofs,” says DOB spokesman Andrew Rudansky “Those standards set requirements for green roof assemblies, such as the type of growth medium, depth, required drainage and types of plants that are acceptable.”
However, Alan Burchell, principal at green-building consultancy Urbanstrong, says this section of the Building Code does not provide enough information because there are many types of green roofs and factors involved. He says more details need to be provided.
“When somebody asks us for a green roof, the first thing we ask is what they want to achieve,” Burchell says. “Is their goal insulation and energy conservation? Are they aiming to manage stormwater runoff? Is it important to them to contribute to lower carbon-dioxide levels? How important is a habitat for birds and butterflies? Will they want or need an irrigation system? Maybe they want to incorporate decking, or agriculture? There are so many different options.”
The DOB says clarification is forthcoming.
“The department will be providing further details shortly,” says Rudansky, noting that boards replacing a roof or building a new structure will need to comply with Local Laws 92 and 94. “The DOB will take enforcement actions. This will include the issuance of violations if we receive complaints regarding maintenance issues with green roofs.”
