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Local Law 97 (also referred to as LL97) is part of the Climate Mobilization Act, which was enacted in 2019 and establishes limits on greenhouse gas (GHG) emissions that buildings 25,000 SF or greater will be allowed to produce beginning in 2024. The allowable GHG emissions are based upon building type and are scheduled to be reduced every five years until 2050 with the goal of New York City achieving carbon neutrality.

This law affects over 15,000 buildings in New York City with 20% of those (approximately 3,000) facing fines beginning in 2025 based on current energy usage and greenhouse gas emissions. The number of buildings facing potential fines in 2030 nearly quadruples to 12,000 as the allowable amount of CO2 emissions is cut by 40% from the 2025 allowable limits. Building Owners are currently required to file annual energy audit reports, as mandated by Local Law 84.

The reports are typically submitted by Managing Agents, Owner’s Representatives, etc; however, those reports will be required to be signed and sealed by a P.E. or R.A. beginning in 2025 and submitted through the NYC Energy Star Portfolio Manager tool where the information will be used to assess potential fines for buildings with excessive greenhouse gas (GHG) emissions.

The law establishes a fine of $268.00 for each metric ton of CO2 a building emits which is over the allowable amount established for each year. The total amount of fines can be substantial if a building’s emissions are significantly over the allowable limits. 

For example, a current Client of Sullivan Engineering, A Rimkus Company manages a seven-story, 25,483 SF condominium building in lower Manhattan. The building is comprised of 22,483 SF of residential apartments on the 2nd through 7th floors (Occupancy Group R-2) and the ground floor features a 3,000 SF restaurant (Occupancy Group A). Based upon the building occupancy, the allowable GHG emissions for this property are calculated as follows:

Occupancy Group
Emissions Limit
Gross Floor Area
Total GHG’s
0.01074 (tCO2e/sf)
3,000 sf
0.00675 (tCO2e/sf)
22,483 sf
Total Allowable GHG Emissions:

The building has been filing their annual energy benchmarking reports in accordance with Local Law 84 and the latest GHG emissions report indicates a total of 346 tCO2e/yr which is 162 tCO2e/yr over the 2024 – 2029 allowable limits. The LL97 penalty assessment for this property would be as follows:

Current GHG Emissions = 346 tCO2e/yr (162 tCO2e/yr over allowable)

Fine Assessment: 162 tCO2e/yr x $268.00 = $43,416.00 / year

The allowable GHG emissions is decreased to 104 tCO2e/yr for the second phase of LL97 in the years 2030 – 2034. The penalty for this property will increase to $65,000 / year if no energy conservation measures are implemented to reduce the current amount of annual GHG emissions.

How Sullivan Engineering, A Rimkus Company Can Help

Sullivan Engineering offers a program to perform a comprehensive energy analysis for existing buildings to determine compliance with Local Law 97. The program includes ASHRAE Level II evaluation of the existing building mechanical systems operations and utility costs. This energy analysis will determine the NYC Benchmarking status and a building’s exposure to LL97 fines. We also perform a comprehensive building envelope survey in conjunction with the mechanical systems ASHRAE Level II evaluation. 

The purpose of the envelope survey is to determine where significant energy loss may be occurring through the roof and facades in the form of deteriorated, poorly insulated roofing and façade assemblies, deteriorated windows that leak excessively, etc. At the conclusion of the ASHRAE and building envelope evaluations, Sullivan Engineering will provide Owners / Managing Agents with a comprehensive report which includes a master plan for implementation of Energy Conservation Measures (ECMs) to reduce or eliminate exposure to LL97 fines.

The ECMs are presented in prioritized, phased approaches to help buildings achieve LL97 compliance in each of the forthcoming five-year periods. For example, our Client in lower Manhattan may elect to implement relatively inexpensive improvements to the building mechanical systems for GHG emissions compliance in the years 2024 – 2029 and then elect to replace their existing deteriorated windows and roofing system with new ones by 2030 to further reduce GHG emissions as the allowable limits decrease by 40% from the 2024 limits.

A wholistic analysis of both the building mechanical systems and envelope assemblies is what is needed to provide the owners with the most comprehensive view of where energy is being lost and what steps may be taken in carefully planned, incremental phases to bring their property into compliance with the forthcoming LL97 regulations.

Contact us to learn more.

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About Sullivan Engineering, A Rimkus Company

Sullivan Engineering provides high-quality building envelope restoration and compliance solutions.

We partner with facilities managers and account executives to provide technical expertise and project management for building envelope restoration, compliance, and maintenance.

Our solutions reduce the overall building life cycle maintenance costs by creating long-lasting, high-quality work for years to come.


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