New York City Local Law 97 caps greenhouse gas emissions from most buildings larger than 25,000 square feet and charges owners $268 for every metric ton of CO2 equivalent they emit over their annual limit. Passed in 2019 as the core of the Climate Mobilization Act, it targets the city’s largest emissions source and tightens its caps in stages, reaching net-zero in 2050.1New York City Council. Climate Mobilization Act The first compliance period runs from calendar year 2024 through 2029, and owners file their first annual emissions reports by May 1.
Does the Law Apply to Your Building?
The 25,000-square-foot threshold is the main trigger. Any single building over that size is covered. So are two or more buildings on the same tax lot that together exceed 50,000 square feet, and condominiums governed by a single board of managers that exceed 50,000 square feet combined.2New York City Administrative Code. Article 320 – Building Energy and Emissions Limits Roughly 50,000 buildings fall inside those lines, including office towers, large multifamily properties, hotels, hospitals, and retail complexes.
Several categories follow different rules. Buildings used primarily for power generation or steam production sit outside the standard caps. City-owned properties and public housing operate under separate frameworks. And a sizable group of residential buildings — those with at least one rent-regulated unit, HDFC-regulated buildings, and buildings in project-based federal housing programs — are not subject to the Article 320 per-ton caps at all. They comply instead through Article 321, which offers two simpler pathways: meeting the 2030 emission limits, or implementing a list of 13 prescribed energy conservation measures (set-point adjustments, pipe insulation, weatherization, lighting upgrades, and similar maintenance-grade work) certified by a retro-commissioning agent.3NYC Department of Buildings. LL97 Compliance Report – Article 321 Failing to file or demonstrate compliance under Article 321 carries a flat $10,000 penalty rather than open-ended per-ton fines.4NYC Department of Buildings. LL97 GHG Emissions Violations
How Your Annual Emission Limit Is Calculated
Every covered building has an annual cap set by its occupancy group and its gross floor area. The law assigns each occupancy group a building emissions intensity limit, measured in metric tons of CO2 equivalent per square foot. Multiply that intensity by your floor area to get your cap in metric tons. The 2024–2029 intensity limits include:5New York City Administrative Code. NYC Admin Code 28-320.3.1 – Annual Building Emissions Limits 2024 Through 2029
- Group B office/business: 0.00846 tCO2e/sf
- Group R-2 multifamily residential: 0.00675 tCO2e/sf
- Group M retail/mercantile: 0.01181 tCO2e/sf
- Group R-1 hotels: 0.00987 tCO2e/sf
- Group A assembly: 0.01074 tCO2e/sf
- Group B hospitals, labs, and emergency facilities: 0.02381 tCO2e/sf
A 100,000-square-foot office building (Group B) therefore has a cap of about 846 metric tons a year. If it emits 1,200, penalties attach to the 354-ton overage.
Mixed-use buildings calculate a combined limit. Take each occupancy section’s square footage, multiply by that group’s intensity limit, and add the results. A 60,000-square-foot office with 40,000 square feet of retail runs the calculation twice and sums the two numbers for its annual cap.5New York City Administrative Code. NYC Admin Code 28-320.3.1 – Annual Building Emissions Limits 2024 Through 2029
The caps tighten in the second compliance period (2030–2034), with limits roughly 40 percent lower for most building types, and they keep stepping down through 2049 before the 2050 net-zero requirement.6NYC Department of Buildings. LL97 Greenhouse Gas Emissions Reduction
How Your Building’s Actual Emissions Are Measured
Reported emissions come from multiplying each fuel source’s annual consumption by a greenhouse gas coefficient the city publishes. For 2024–2029, the key coefficients are:7NYC Department of Buildings. Local Law 97 Emissions Coefficients
- Utility electricity: 0.000288962 tCO2e per kWh
- Natural gas: 0.00005311 tCO2e per kBtu
- Fuel oil #2: 0.00007421 tCO2e per kBtu
- Fuel oil #4: 0.00007529 tCO2e per kBtu
- District steam: 0.00004493 tCO2e per kBtu
Add the results across every fuel the building uses and compare the total to the cap. Electricity coefficients are expected to decrease in later periods as the grid gets cleaner, which is why buildings that electrify heating and hot water now tend to be better positioned for the stricter caps ahead.
The Annual Report Due May 1
Every covered building owner must file a greenhouse gas emissions report for the prior calendar year by May 1. The report has to be certified by a Registered Design Professional, meaning a licensed architect or professional engineer, who verifies the calculations and states whether the building met its limit. If a building was over the cap the year before and has since come back into compliance, the report must describe how.8New York City Administrative Code. NYC Admin Code 28-320.3.7 – Reports Required To Be Filed by Owner
The filing itself moves through three city and federal platforms: fees are paid through DOB NOW, energy data is submitted through the EPA’s Energy Star Portfolio Manager, and the compliance report is filed through the Department of Buildings’ BEAM portal.9NYC Department of Buildings. Local Law 97 Compliance Report Submission Process
Filing fees run $210 for a simple Article 320 emissions report, $615 for a complex one, and $210 for an Article 321 compliance report. A good faith effort filing adds a separate $950 fee, and a 60-day filing extension costs $60.10NYC Department of Buildings. Local Law 97 Combined and Aggregate Reports User Guide
What Non-Compliance Costs
Going over the cap costs $268 per metric ton of CO2 equivalent above the limit, assessed every year the building stays over. A large commercial property 500 tons over its limit pays $134,000 for that year alone.4NYC Department of Buildings. LL97 GHG Emissions Violations
Missing the May 1 deadline is a separate and often larger problem. The late-filing penalty is $0.50 per square foot of floor area for every month the report is late. On a 200,000-square-foot building, that is $100,000 a month. The report has to be filed on time even if the building is over its cap, because the two penalties stack.4NYC Department of Buildings. LL97 GHG Emissions Violations
Ways to Reduce What You Owe
Beneficial Electrification Credits
Owners who replace fossil fuel systems with high-efficiency electric equipment, mainly heat pumps for space heating and hot water, earn a beneficial electrification credit that subtracts from reported emissions. Equipment installed before 2027 earns double the credit, and all eligible equipment must be installed before 2030. Credits from one installation can be applied across multiple compliance years between 2026 and 2034, though each year’s credit must be applied in full to a single year. No separate application is required; the credit is recognized through the annual LL97 filing.11NYC Accelerator. Beneficial Electrification Credit
Renewable Energy Credits
Renewable Energy Credits can offset emissions, but only emissions from utility-supplied electricity. They don’t offset natural gas, fuel oil, or steam, and purchasing them does not by itself get a building into full compliance; any remaining overage still draws penalties. Tier 4 RECs (new renewable generation delivered into New York City) are expected to be available starting in 2026, with projected prices of $30 to $80 per MWh translating to roughly $104 to $277 per ton of CO2 offset, often comparable to or cheaper than the $268 per-ton penalty. Owners who file a decarbonization plan under the good faith effort pathway cannot use RECs during the 2024–2029 period.12NYC Department of Buildings. Renewable Energy Certificate Policy for Local Law 97
Good Faith Effort Mitigation
When a court or administrative tribunal sets penalty amounts, it must consider the owner’s investments in efficiency and emission reductions, compliance history, unforeseeable events outside the owner’s control, financial resources, and whether the penalty would affect facilities critical to human life or safety.13New York City Administrative Code. Local Laws of the City of New York for the Year 2019 – Local Law 97 Owners can qualify for mediated penalty mitigation by meeting prerequisites that include compliance with benchmarking (Local Law 84), lighting and submetering upgrades (Local Law 88), and timely LL97 report filing. Owners who submit a net-zero decarbonization plan with an energy audit, equipment inventory, financing, and milestones can get penalty relief through 2026, but they give up REC use for the first compliance period and face retroactive penalties if they miss their milestones.
Formal Emission Limit Adjustments
The Department of Buildings can grant a formal adjustment to a building’s cap when outside constraints block compliance, such as landmark status, site or physical limitations, or lack of access to energy infrastructure. The owner has to show they tried to purchase offsets and used all available city, state, federal, and utility incentives. A separate financial hardship adjustment exists when the cost of required capital improvements would prevent a reasonable financial return, the owner is ineligible for city-financed energy programs, and offsets and RECs are not available at a reasonable cost. Adjustment application fees run from $300 to $3,540 depending on the type claimed.14New York City Administrative Code. NYC Admin Code 28-320.7 – Adjustment to Applicable Annual Building Emissions Limit
Free Help From NYC Accelerator
The city-funded NYC Accelerator program gives building owners free expert guidance on energy efficiency, electrification, and LL97 compliance. Its Momentum tool helps owners assess their building’s energy profile, model compliance scenarios, and manage retrofit projects. Staff help identify incentives and financing and connect owners with qualified contractors and design professionals.15NYC Accelerator. NYC Accelerator Only a Registered Design Professional can certify and submit the annual report, but Accelerator staff can help an owner understand compliance status and prioritize cost-effective upgrades well before May 1.16NYC Accelerator. NYC Accelerator Steps to LL97 Compliance