Which Roof Repairs Trigger NYC Local Law 92/94 And Which Do Not

The aim of this post is to clarify for building owners some of the confusion around which types of rooftop work trigger Local Laws 92/94, and just as importantly, which do not. 

I have found this confusion seems to not just be limited to co-op and condo boards and other building owners. Many of our colleagues, fellow green roof installers and solar installers, seem to have it wrong as well. If you know anyone who could benefit from this post, then definitely consider sharing it with them. 

So then, first a quick re-cap:

NYC Local Law 92/94 Summary

Local Laws 92/94 went into effect in NYC on November 15, 2019 as part of a broader package of environmental and energy laws called the Climate Mobilization Act or New York’s “Green New Deal”.

LL 92/94 effectively requires that certain NYC buildings cover 100% of their roof (with some exceptions) with what’s called a ‘sustainable roofing zone.’  I’m skipping a lot of details here but that essentially means either a vegetated ‘Green Roof’ or a rooftop Solar Photovoltaic system.  (Whether and when it makes more sense to install a green roof or solar is covered in a separate post.)

Local Law 92 refers to new construction.

Local Law 94 refers to existing buildings undergoing certain retrofits.  And which types of roof work will trigger this requirement to cover the roof with either a green roof or solar panels IS PRECISELY WHERE THE CONFUSION LIES.

Do Waterproofing Membrane Repairs Trigger NYC Local Law 92/94?

Building owners across the city who are just planning to repair or replace their waterproofing membrane are worried unnecessarily. They are under the false impression this work will trigger Local Law 94 and be required to install a Green Roof or Solar.  Sadly, some of them are even being falsely told this by aggressive rooftop solar contractors.  And to be fair, some roofing contractors are genuinely confused. 

The reality is that simple roof membrane replacements will not trigger Local Law 92/94. You can just replace your waterproofing membrane without installing a Sustainable Roofing Zone. After the confusion around the wording of the law’s language, the Mayor’s office released an FAQ bulletin to clarify once and for all:

Which types of work on existing roofs DO trigger NYC Local Law 92/94?

The law states that Local Law 94 will be triggered by “work involving the replacing of an entire existing roof deck or roof assembly.”

I believe the misinterpretation of the law’s language by many lay specifically in the use of the phrase “an entire existing roof deck or roof assembly...."  

What types of material layers make up a typical roof assembly?

A roof assembly is made up of several layers. They come in many different combinations and arrangements, but for illustrative purposes, here is a typical roof assembly:

What is the difference between a roof covering, a waterproofing membrane, and a roof assembly?

While the law’s wording  does go on to define a roof assembly as including a “roof covering” (aka waterproofing membrane), the roof covering is one of many elements listed in the assembly...but the roof covering on its own does not constitute the assembly as per the law’s own definition:

"A roof assembly includes the roof deck, substrate or thermal barrier, insulation, vapor retarder and roof covering."  Ergo, if all an owner is doing is replacing the roof covering (waterproofing membrane), this does not mean they are replacing the entire roof deck or roof assembly, which is required in order to trigger Local Law 94. 

Don't get me wrong, it sure would be a nice boost to our business if the law was that ANY roof work triggered a mandatory installation of a green roof or solar, given that Urbanstrong sells both...but that's simply not the case.  I hope this helps.   -Alan