Sustainable Roofing

A Comprehensive Guide to Local Law 92 and Local Law 94 in New York City

Understanding Local Law 92 and Local Law 94: An Overview

The Climate Mobilization Act of 2019 introduced LL92 and 94 alongside Local Law 97. Sustainable roofing systems or green roofs have become mandatory as part of local law 92/94. Both new and existing buildings where roofs need to be renovated or replaced must comply with the LL92 and 94 requirements. Dive deeper to learn more about local law 92 and 94.

What Do the Laws Entail?

NYC local law 92 and 94 make it mandatory to install sustainable roofing zones for new constructions as well as roof renovations. The sustainable roofing solutions under LL92 and LL94 revolve around a solar panel power generation system, a green roof, or a combination of both.
LL94 updates the cool roof requirements of local law 21 and creates the bulk of the green roof legislation. LL92 makes the same things compulsory for smaller buildings.
LL92 and LL94 are applicable for renovations in horizontal as well as vertical constructions in an existing roof that needs a permit. They are the first laws under the Climate Mobilization Act that have already been implemented because most of them will be applicable from 2024. The local law 92/94 of 2019 will help make NYC skylines the most sustainable in the world.

Compliance with Local Law 92 and 94

All major renovations and new constructions should install a green roof system. Building owners focused on these constructions should take the following steps:

  • Determine whether green roofs, solar panels, or both are suitable according to the roof space and shade
  • Hiring a professional to perform structural analysis of the roof
  • Ensuring compliance with the applicable building codes

In most shaded buildings, solar panels are not an option. However, green roofs can be a sustainable option even when the building roof is under shade for most of the day.

But for some building owners, their roofs have enough shade for either option. In that case, compliance with LL92 and 94 won’t be necessary.

Exemptions from L92 and LL94 Requirements

All rooftops in NYC need to comply with the local law 94 and 92 requirements until they belong to the following categories:

  • Roofs that must be kept aside to meet NYC building codes and zoning regulations
  • Roof areas where water towers, mechanical equipment, antennas, and other important devices are installed
  • Roof areas covered by stormwater management system components
  • Existing terraces that haven’t been voluntarily installed without meeting the NYC Zoning Resolution. The setback areas should be under 25% of the biggest floor plate area in the building to be eligible for the exemption.
  • Recreational areas crucial for the occupancy classification of the building, like sports areas in schools
  • Roofs without the capacity to handle a 4 KW solar plant
  • Roofs with a slope beyond 2:12 make them inappropriate for a green roof.
  • Any area which is considered unsuitable for a solar or green roof system by the NYC Department of Buildings. For instance, it is applicable for buildings that cannot withstand the weight of a sustainable roofing zone.

Rooftops amidst the affordable housing sector are also subject to LL92/94 requirements. But the laws will be fully applicable only after 15 November 2024. Until then, these buildings will only have to follow the LL92/94 requirements up to a certain extent determined by the NYC Department of Housing Preservation and Development (HPD). The reduced requirements are applicable to the following buildings:

  • Buildings with one or more dwellings where occupancy is limited by income
  • Buildings under the alternative enforcement program in the NYC Administrative Code
  • Buildings owned by the Department of HPD


Solar Panels Vs Green Roofs: Which One to Choose?


To comply with the Local Law 92/94 of 2019 sustainable roof zone NYC requirements, building owners can either install a solar or green roof. Both solar panels and green roofs are valuable for making your building more energy-efficient. It is best to use a combination of both if possible. However, solar panels and green roofs are not each other’s alternative in terms of environmental benefits.

A solar panel system will improve the energy usage of your building by changing the power supply. Instead of depending on nonrenewable fossil fuels, solar panels will power your building through renewable electricity with no carbon footprint. Solar panels offer energy efficiency while using electrical appliances like water heaters and heat pumps.
Green roofs come with a lot of environmental benefits and versatility. For instance, green roofs are perfect for creating a recreational space inside your building. Moreover, the area will be suitable for rooftop agriculture and enhance air quality.
Green roofs support energy efficiency by providing better insulation to your buildings. With improved insulation, your building will rely less on energy systems for heating and cooling. Therefore, you will be able to save energy consumption costs and increase the durability of your HVAC systems.

Ending Note

Building owners often struggle with complying with the Local Law 94 and 92 requirements. That’s when they are in need of professionals to help with local law compliance. The experts at The Cotocon Group will come to your rescue with years of experience and the utmost professionalism. Contact us today for your free consultation!


What changes did LL94 bring to cool roof requirements?

LL94 made cool roofs cooler with more stringent emittance and reflectance requirements for flat roofs. The law also mandated it necessary for pitched roofs and roofs under solar panels to be cool. Since green roofs are also cool, all roofs in New York City will now be cool.

Can an incomplete green roof or solar array cause a delay in getting my occupancy certificate?

The Department of Building will issue your temporary certificate of occupancy if the space seems safe. Considering green roofs or solar arrays are not required to ensure the basic safety of buildings, they won’t cause any delay in getting your occupancy certificate. However, you should comply with the green roof or solar array requirements to avoid other penalties.

What is the relationship between LL92 and 94 with LL97’s carbon limit for buildings?

Solar energy systems required as part of LL92 and LL94 can enable building owners to comply with the carbon limits of local law 97. Sustainable roof systems like green roofs can promote easy compliance with the LL97 requirements.

How can LL92 and 94 compliance help during the winter season?

LL92 and 94 compliance revolve around the solar panel and green roof installations. Solar panels help reduce your energy bills during the winter by producing energy. Green roofs offer better insulation than standard roof systems to lower heating costs and increase comfort.

Can LL92 and LL94 compliance help with LEED certification?

Installing green roofs can help your building become LEED certified. The certification will instantly increase property value and make it a top choice for people looking for sustainable residences. Apart from the energy efficiency and cost-saving benefits of LL92 and LL94, the LEED certification is a major advantage.

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