Cities are setting goals on a pathway to zero or near-zero carbon, but they must address their biggest source of carbon emissions—existing buildings—using thoughtful policies to swiftly and cost-effectively deploy energy efficiency and distributed renewable energy systems.

Packaging multiple policy elements together can unlock substantial carbon emissions reductions while driving job creation, increasing tax revenue, and developing new markets for renewable energy and energy efficiency. Understanding baseline energy consumption and evaluating policies using a citywide model are critical to understanding the efficacy and potential impact of a policy targeting existing buildings.

Rocky Mountain Institute’s work with a tier 1 city led to a cost-optimized point-of-sale policy that can yield over $4 billion in lifetime energy cost savings at full policy implementation and—in conjunction with existing policies—reduce CO2e emissions in the buildings sector by 67 percent, in support of the City’s 2050 goal to reduce greenhouse gas emissions by 80 percent. The actions outlined in this paper can enable cities to start driving carbon emissions reductions in their existing buildings.