Retrofitting California’s older housing stock is a major challenge for electrification and resilience. In regions like San Diego—where most of the 800,000 buildings built before 1978 are ill-equipped for upgrades—homes often require extensive pre-work such as roofing repairs, panel and insulation upgrades, or appliance replacements before heat pumps and other zero-emission technologies can be installed. Each building’s unique conditions make retrofits costly and highly individualized, creating stacked barriers for low- and moderate-income homeowners. Local energy and air-quality agencies in the Inland Empire have emphasized that the transition to zero-emission housing must prioritize affordability and equity to ensure retrofit programs reduce, rather than reinforce, existing economic divides.