Local Law 97, Explained: Carbon Caps and What They Cost
LL97 caps the carbon emissions of most NYC buildings over 25,000 square feet. The caps tighten over time, and going over means per-ton fines. Here's how your cap is calculated, and how to tell where your building stands.
- Applies to
- Most buildings over 25,000 sq ft, and tax lots with two or more buildings over 50,000 sq ft combined
- Reports due
- May 1, every year
- Penalty
- $268 per metric ton of CO2e over the limit
- Signed by
- A registered design professional (PE or RA)
Local Law 97 sets an annual carbon emissions limit for most large buildings in New York City. The first compliance period runs from 2024 to 2029. Limits drop sharply in 2030 and continue to tighten toward net zero by 2050. Each year you file a report, certified by a registered design professional, comparing your building’s emissions with its limit.
How your limit is calculated
Your limit is the floor area of each occupancy group in the building multiplied by that group’s emissions intensity limit, added together. A mixed-use building with offices and apartments gets a blended limit.
| Occupancy group | 2024–2029 limit | 2030–2034 limit |
|---|---|---|
| B (office) | 0.00846 tCO2e/sf | 0.00453 tCO2e/sf |
| R-2 (multifamily) | 0.00675 tCO2e/sf | 0.00407 tCO2e/sf |
How your emissions are calculated
Emissions are your annual use of each fuel multiplied by a carbon coefficient set in the law. For the first compliance period:
| Energy source | Coefficient (2024–2029) |
|---|---|
| Electricity | 0.000288962 tCO2e/kWh |
| Natural gas | 0.00005311 tCO2e/kBtu |
| Fuel oil #2 | 0.00007421 tCO2e/kBtu |
| Fuel oil #4 | 0.00007529 tCO2e/kBtu |
| District steam | 0.00004493 tCO2e/kBtu |
A worked example
Take a 100,000 sq ft office building that emits 950 tCO2e per year. Its 2024–2029 limit is 846 tCO2e, so it is 104 tons over: an annual penalty of $27,872. In 2030 the limit falls to 453 tCO2e. At the same emissions the building is 497 tons over, and the annual penalty rises to $133,196.
Filing late costs extra. Failing to submit the annual report carries a penalty of $0.50 per square foot per month until it is filed.
Different pathways
Most covered buildings comply under Article 320, which sets the emissions limits above. Buildings under Article 321, for example those where more than 35% of units are rent regulated, follow a prescriptive path instead: a defined list of energy conservation measures rather than a numeric limit. DOB rules also provide limited adjustment pathways for owners who cannot meet their limit on schedule.
How to tell where you stand
- Start with last year’s benchmarking data for each fuel.
- Multiply each fuel by its coefficient and add the results.
- Calculate your limit for 2024–2029 and for 2030–2034 from your floor area by occupancy group.
- Compare the two. The gap in 2030 is the number to plan around.
The Borealis Property Explorer runs this comparison for any NYC building from its address, BBL or BIN. For a filing, an RDP needs to verify the inputs.
Limits and coefficients are from Local Law 97 of 2019 as amended. Confirm current DOB rules before filing.
