The Climate Mobilization Act & Local Law 97

Author: Kurt Karaisz
Date: May 14, 2021

The Climate Mobilization Act & Local Law 97

In April 2019, the New York City Council passed the Climate Mobilization Act, a legislative package aimed towards decreasing carbon emissions in New York City. This package was made with the intent of aligning NYC with the emission reduction targets set out in the Paris Agreement, with the ultimate aim of achieving carbon neutrality by 2050.

The centerpiece of the Climate Mobilization Act is Local Law 97. In New York, over 70% of greenhouse gas emissions come from buildings, according to the Urban Green Council. Local Law 97 works to reduce this figure by placing emissions limits on both commercial and residential NYC buildings that are over a certain size. These limits will become increasingly stringent over time. The carbon emission caps will start in 2024, with an overall target of 40% carbon reduction from a 2005 baseline by 2030, and an 80% reduction by 2050.

Does Local Law 97 Apply to Your Building

Local Law 97 applies to following buildings:

  1. Existing and new commercial and residential buildings that exceed 25,000 sqft
  2. Tax lots including multiple buildings with a combined size which exceeds 50,000 sqft
  3. Groups of two or more buildings held in the condominium form of ownership that are governed by the same board of managers, and exceed 50,000 sqft.

There are several exceptions to Local Law 97: city-owned buildings, houses of worship, rent-regulated buildings, and other forms of affordable housing are excluded from the requirements. However, it should be noted that although these buildings are exempt from Local Law 97, they have their own separate set of requirements.

But, in general, if a property is subject to the NYC Benchmarking Law (Local Law 84), it is also subject to Local Law 97.

Timeline of Implementation

Though touted as aggressive, the compliance timeline for Local Law 97 is designed to give building owners sufficient time to reach compliance.

There are 2 initial compliance periods detailed in Local Law 97: 2024-2029, and 2030-2034. Emission limits are not yet set for compliance beyond 2034. Future limits are to be determined by the Department of Buildings for the periods 2035-2039, 2040-2049 and 2050+ by January 1st, 2023.

The first limit will be set on January 1st 2024. In 2024-2029, greenhouse gas emission limits are set, and estimated to affect ~20% of existing buildings. In 2030-2034, the limits are tightened, and estimated to affect ~75% of existing buildings. The exact emission limits are determined based on occupancy group.


Starting in 2025, affected building owners will need to file an emission report by May 1st of each year. This report must be certified by a registered design professional, and can be submitted online to the office of building energy and emissions performance.

Building emission limits are detailed in Local Law 97 through a metric called building emission intensity. This metric is obtained by dividing the building emissions by the floor area, and is expressed in metric tons of carbon dioxide per square foot per year. Different occupancy groups have different building emission intensity limits.

Building emissions are calculated based on energy consumption. Local Law 97 details different emissions factors for each source of energy (e.g. natural gas, electricity, fuel oil, etc..) These factors are based on the associated carbon pollution that each energy source generates. To determine a building’s total emissions, the building’s energy consumption (which is required to be reported/recorded by Local Law 84) is multiplied by the appropriate emissions factors and then summed up.

There are several ways to determine a building’s current annual emissions intensity. Building energy benchmarking data can be found through ENERGYSTAR, and also Urban Green Council’s tool can be used to search up emissions data by address. But, in general, if a property is subject to the NYC Benchmarking Law (Local Law 84), it is also subject to Local Law 97.

If a building cannot reach compliance through solely reducing energy use, the law provides some alternate solutions. Building owners can reduce their emission requirements if they demonstrate the purchase or use of one of the following:

  1. Greenhouse gas offsets: A greenhouse gas offset is a reduction in emissions used to compensate for emissions that occur elsewhere. For example, a building owner over the emissions limit can purchase offset credits for shares of a forest restoration project, and these credits would count as a reduction to the building’s emissions due to the emissions saved by the forest project.
  2. Renewable energy credits (RECs): Renewable energy credits represent energy generated through renewable sources, and can be purchased.
  3. Use of clean distributed energy resources (DERs): Distributed energy resources are energy systems (such as solar panels) that are located at houses or businesses to provide them with power.

The city is also exploring an emissions trading program, where buildings that surpass their target emissions goals can sell to buildings that do not.

Penalties for Non-compliance

Buildings that fail to comply will incur a fine of $268 per metric ton that their carbon footprint exceeds annually. A failure to report carbon emissions can incur a fine of up to $0.50 per square foot for each month that the report is not filed. Filing a false report can incur fine of up to $500,000, as well as civil penalties and up to 30 days of imprisonment.

Methods to Reach Compliance

There are many different strategies building owners can use to improve the efficiency of their buildings. HVAC and lighting are the largest contributors to most buildings’ energy use, and account for approximately 58% of the average NYC building’s energy use, per a 2015 benchmarking report by the Urban Green Council. As such, many energy efficiency measures are focused on improving electrical and mechanical equipment.

Lighting energy use can be reduced through the utilization of energy-efficient LED lighting. LED lights use ~75% less energy than old-fashioned incandescent light bulbs, and also last much longer. Occupancy sensors are another measure used to reduce lighting energy loads. Some advanced occupancy sensors can be equipped to detect the space temperature along with occupancy, and provide feedback to the HVAC system, which can then adjust for occupancy to provide the required output when needed.

HVAC equipment is ever-improving in terms of energy efficiency. Replacing old, inefficient units with newer efficient models is an effective way to improve a building’s overall efficiency. For instance, older boilers operate at around 65% efficiency, while newer condensing boilers operate at 95% efficiency. Adding smart controls, such as Building Management Systems (BMS) also can reduce energy consumption by optimizing operation.

While it can be helpful to utilize energy-efficient solutions such as LED lighting and variable refrigerant flow systems, a building’s envelope and internal layout have a large impact on lighting requirements and HVAC loads.

The building envelope is the separation of the interior and exterior of a building, it includes windows, doors, roof, foundation, walls and insulation. An inefficient building envelope can account for a substantial amount of energy loss. Deficient insulation and air leakage are the two main causes for envelope inefficiency. A building with deficient insulation will conduct significantly more heat through the roof, walls and floor. This heat conduction translates into more heat gain in the summer, and more heat loss in the winter. Air leakage, which is typically found at windows and doors, causes a direct loss of conditioned air to the outdoors. An efficient envelope, which would include energy efficient windows, well-sealed doors, and additional thermal insulation of walls, basement slabs and foundations can reduce heat loss by up to 50 percent, and greatly reduces the energy needs from HVAC equipment.