Local Law 97: each building's gap to its limit, tracked monthly
Local Law 97 caps greenhouse gas emissions from New York City's largest buildings, with limits that tightened in 2024 and tighten again in 2030. Aqueduct meters every fuel per building and shows the gap to the limit during the year, not after the report is filed.
Who it applies to
Buildings over 25,000 gross square feet, two or more buildings on one tax lot that together exceed 50,000, and condominium buildings under one board that together exceed 50,000. That is about 50,000 of the city's 1.1 million buildings.
Most private buildings fall under Article 320 of the Administrative Code and must stay under a numeric limit. Certain affordable housing and houses of worship fall under Article 321, which allows a set of prescriptive measures instead. Each report is certified by a registered design professional.
How the limit and the emissions are calculated
From the NYC Department of Buildings and rule 1 RCNY 103-14. Your registered design professional does the calculation and files.
| Requirement | What it asks for | Data Aqueduct supplies |
|---|---|---|
| The limit | Gross floor area multiplied by an emissions factor for each property type. | Floor area and use type per building, held in aQ Core. |
| The emissions | Annual use of each fuel multiplied by its coefficient. | Electricity, gas, steam and oil per building, metered monthly. |
| Renewable energy credits | Apply only to electricity emissions; on-site solar and storage can be deducted. | Grid import and solar generation metered separately. |
| Hospitals, 28-320.9 | Not-for-profit hospitals that applied must stay at or below a share of their 2018 emissions. | The 2018 baseline and current year on the same meter basis. |
Penalty and dates
Penalty per metric ton of CO2e over the limit, each year.
Source: NYC Department of BuildingsAnnual report deadline for the previous calendar year; the first, for 2024, was due 1 May 2025.
Source: NYC Department of BuildingsLimits tighten; DOB estimated about 75% of covered properties would need to act to comply.
Source: NYC Department of BuildingsRelated standards
Sources3 references cited on this page
sites in 21 countries run on Aqueduct.
and 9 clinics in one of India’s top hospital chains.
US airport running water intelligence on Aqueduct.
of commercial real estate under Aqueduct.
FMCG manufacturing campus.
operations run on Aqueduct.
Related
Common questions
Because the penalty is set by the whole year. A building heading over its limit in spring still has months to fix after-hours HVAC, simultaneous heating and cooling or a failed economizer. In December it does not.
Sometimes, against the 2024 to 2029 limits. The 2030 limits are lower, so capital work and electrification are best planned with each building's gap already known. Aqueduct shows how much of the gap schedules and fault fixes have closed, which sizes the capital work that remains.
A hot summer or cold winter raises fuel use and so emissions. Aqueduct normalizes consumption on cooling and heating degree days, so a retrofit is judged on its real effect.
A building above that size must stay under an emissions cap that scales with its square footage and occupancy type, and report every year by 1 May. Aqueduct gives your design professional each fuel's monthly use per building, so the annual calculation starts from readings. See building performance standards.
See Aqueduct on your own facility.
Bring a site, a utility bill or a question. We will show you where the loss is.