LL87

Local Law 87 requires larger buildings to undergo, on a recurring multi-year cycle, an energy audit — a professional assessment of the building's energy-using systems and cost-effective improvement measures — and retro-commissioning, the tune-up process verifying those systems actually operate as designed. Results file with the city; the obligation recurs by schedule, and non-filing accrues penalties.

In the decarbonization stack, LL87 is the diagnostic layer: benchmarking (LL84) measures outcomes, the audit explains them, and the emissions law (LL97) prices them. For analysis, audit filings and their findings — where obtainable — describe a building's efficiency opportunities, and filing compliance itself is another datable obligation on the record.