About FeeWarden

Short answer: FeeWarden is a free tool that estimates what each NYC building could owe under Local Law 97, today and from 2030, using the building's own energy filing.

What it does

Local Law 97 charges $268 for every metric ton of CO2 equivalent a building emits above its limit. FeeWarden applies the law's limits and emissions factors to the energy use each building reports under Local Law 84, and shows the result as a dollar figure and a chart.

Where the numbers come from

• Energy use: NYC Open Data, Local Law 84 benchmarking.
• Limits and factors: the Local Law 97 text and NYC Department of Buildings guidance.
• Every input and step is on the method page, and the results are in the data download.

What it is not

The figures are planning estimates. They are not legal, engineering or compliance advice, and they are not determinations by the NYC Department of Buildings. The department decides what a building owes.

Who runs it

FeeWarden is an independent project that turns the city's public energy filings into per-building Local Law 97 estimates.

Corrections

If a building's figure looks wrong, the cause is usually the energy filing or the property type. Use the request form on the building's page and say what looks off.