A comprehensive and detailed explanation from the NYC DOB can also be found here: Local Law 88 According to New York City NYC DOB (builtengineers.com)
What is Local Law 88?
LL88 of 2009—and its subsequent expansions with Local Law 132 and 134, both of 2016—requires common areas in residential buildings greater than 25,000 square feet and all areas in non-residential buildings greater than 25,000 square feet to upgrade lighting to meet current New York City Energy Conservation Code standards by 2025. The original law and its subsequent expansions also require all non-residential buildings greater than 25,000 square feet to install electrical sub-meters for each large non-residential tenant space greater than 5,000 square feet and provide monthly energy statements. The compliance deadline for both the lighting and sub-metering requirements is 2025.
Details of Local Law 88: Submetering
With the submetering requirements listed in Local Law 88, in addition to the installation of a meter as well as providing monthly statements detailing usage, the law requires floors with multiple tenants and a single meter to detail the consumption and percentage of the area corresponding to the tenant receiving the statement.
If any area can be broken down into sections according to the details stated in the law, submetering is also necessary. The NYC DOB will accept gradual upgrades, as abrupt service disruption when tenants are present. The DOB recommends planned and scheduled upgrades by building owners so that a turnover to submetering can be installed during a tenant turnover.
Details of Local Law 88: Lighting Upgrades
Any property that meets any of the following requirements is subject to Local law 88:
Single buildings with at least 50,000 sq. ft. of floor space
Groups of two or more buildings under the same tax lot, adding up at least 100,000 sq. ft.
Groups of two or more buildings under the condominium form of ownership, adding up at least 100,000 sq. ft.
It is important to note that properties classified under occupancy groups R-2 and R-3 are exempt from both lighting upgrades and submetering, but must submit a report to the NYC DOB, demonstrating how the property is exempt. Houses of worship under occupancy group A-3 are exempt from lighting upgrades, but are subject to metering and reporting requirements. Small residential properties inhabited by 1 to 3 families are fully exempt from LL88, which means not even the exemption report is required.
It is also noteworthy that lighting system components do not require an upgrade if they meet NYC energy code requirements applicable after July 1, 2010. The same applies for areas with a lighting power density that meets the code, as long as these areas are completely isolated from the rest of the building by doors and floor-to-ceiling divisions.