News

Sustainable Roofs Required and Deadline Clarified by DOB

Posted on October, 10 2019

A new requirement for sustainable roofs will soon become effective in New York City.  Local Laws 92 and 94 of 2019 were enacted earlier this year to require that roofs of some buildings be covered by a green roof or solar panels beginning November 15, 2019.

Every new building, enlargement, and roof deck or roof assembly replacement will be required to provide a sustainable roofing zone if construction documents are approved after November 15 th. DOB applications that are approved prior to November 15 th do not need to comply with the sustainable roof requirements of Local Laws 92 and 94 of 2019. The Department of Buildings (DOB) will be adding a Required Item regarding Local Law 92/94 to all New Building and enlargement applications that have not received approval by November 14 th at 3:00 PM.

It is important to note that not all roof work at existing buildings will be subject to these requirements. Sustainable roofs will be required when the work includes replacement of the roof deck – the structural surface to which insulation, roofing and waterproofing system is applied not including the supporting members or vertical supports. Sustainable roofs will also be required when the scope of work includes replacement of the roof assembly – the system proving weather protection including roof covering, vapor retarder, insulation, substrate or thermal barrier, and roof deck. A sustainable roof is not required for a project consisting of only a roof replacement – removal and replacement of existing roof covering (covering is applied to roof deck for weather resistance, fire classification, or appearance) including repair of damaged substrate.

A sustainable roofing zone is an area of a roof that has a solar photovoltaic electricity generating system, a green roof system, or a combination of the two. Any such zone 200 SF or less must provide at least 4kW of solar photovoltaic electricity generating capacity or when that cannot be provided have a green roof system. There are some exceptions such as setbacks or access required by the Fire Code, Construction Codes, or Zoning Resolution; areas with rooftop structures and mechanical equipment; small setback terraces; recreational spaces; roofs with a slope steeper that 17% that cannot generate 4kW of solar electricity; and when the DOB determines site conditions are not favorable for a sustainable roof.

Local Law 92/94 of 2019 added a new sections to the Administrative Code (AC) Building Code (BC) which details the requirements for sustainable roofing zones. AC 28-101.4.3 and BC 1511.2 currently have not been incorporated into the online publication of the Codes, for content see Local Laws below. Additionally the DOB published Buildings Bulletin 2019-010 which further clarifies the new requirements, see link below.

For more information about the approaching deadline and how sustainable roofs impact your project contact your Design 2147 project manager today.