In April 2019, the New York City Council passed Local Law 97 as part of the Climate Mobilization Act, impacting buildings larger than 25,000 s/f. A few months later, Philadelphia followed suit, passing a similar bill for the creation of the Building Energy Performance Program, impacting buildings over 50,000 s/f. Both acts serve as a commitment to cut greenhouse gas emissions by at least half over a near term horizon. The expectations are that the existing buildings will improve their energy efficiency, decreasing the consumption of energy and greenhouse gas emission as a result. But what do the acts mean for the owners and operators of buildings in these cities? In order to meet these requirements, building owners and operators need to determine the timing based on the size of their building and take actions to assure proper upgrades are made to meet the requirements and defined timelines.