Old homes, new inequities: Building stock drives racial disparities in heat pump use in the United States

The unprecedented scale of the clean energy transition presents a unique opportunity to address energy injustice through adoption of new technologies. However, few studies have examined adoption disparities for heat pumps—a key decarbonization technology—and the factors driving these disparities. Using household-level data, we demonstrate that racial and ethnic minority households are less likely to use heat pumps across geographic scales from state to ZIP code. To explore potential explanations, we assess the determinants of heat pump use from household-level attributes. Our findings reveal that differences in building age—a factor relatively overlooked in previous literature—explain a much larger portion of the racial disparity in heat pump use than income and homeownership. Minority groups are more likely to reside in older buildings, even when controlling for income and wealth, and thus face higher installation costs and lower future returns. Notably, the largest racial gap in building age is found among the lowest income and wealth groups. Our results indicate that income-based subsidies or policy supports are inefficient in addressing broader social inequality in heat pump adoption. Including both building attributes and income into tiered subsidy programs could present a promising policy alternative.