Heat pumps are recognized as a primary path to decarbonization. The International Energy Agency has stated that, “Heat pumps, powered by low‐emissions electricity, are the central technology in the global transition to secure and sustainable heating.” In early-adopter communities, virtually all new buildings are built with heat pumps, or soon will be. The Air Conditioning, Heating, and Refrigeration Institute (AHRI) reports that air source heat pump shipments almost tripled in the past ten years. However, implementation in building retrofits is only in its early stages, and anecdotal evidence suggests that these retrofits are largely limited to market-rate housing, and that retrofits in single-family housing in disadvantaged communities have barely begun.