Aging Housing Stock Raises Pre-Retrofit Costs and Complexity. California’s older housing stock creates major barriers to electrification and resilience upgrades. Many homes require costly pre-work—such as electrical panel upgrades, insulation improvements, roofing repairs, or appliance replacements—before zero-emission technologies can be installed. For historic or complex buildings, cumbersome permitting and compliance requirements further slow implementation. Together, these building-specific conditions make retrofits difficult to scale and disproportionately burden low- and moderate-income households, risking widened inequities without affordability-focused program design.

• Illustrative example: In San Diego an estimated 800,000 buildings built before 1978 lack the electrical capacity or structural readiness for electrification, driving up retrofit costs and extending permitting timelines for clean-energy upgrades.