Beyond efficiency: Disentangling structural and behavioral sufficiency in U.S. residential decarbonization pathways

Shuhaib Nawawi , Parth Vaishnav, Xiaoyang Zhong, Morgan R Edwards, Alessio Mastrucci

Decarbonization strategies in the residential sector have largely focused on lowering the carbon intensity of energy supply and improving end-use efficiency. Sufficiency, defined as avoiding unnecessary energy demand while maintaining well-being, remains largely absent from national energy system analyses, obscuring the relative and combined roles of efficiency and sufficiency in reducing energy demand. Here, we disentangle the effects of structural and behavioral sufficiency on residential energy demand and emissions, and quantify their individual and combined effects alongside efficiency improvements, including electrification. Using an integrated modelling framework that links U.S. housing stock turnover to hourly building energy demand, we find that floorspace expands by 55% from 2020 to 2050 under business-as-usual trends, increasing energy demand by 11%. Relative to this 2050 trajectory, efficiency and structural sufficiency reduce demand by 18% and 31%, and by 45% when combined. Adopting conservative, health-informed thermostat setpoints further reduces energy demand by 31–33%. These results show that accounting for sufficiency changes the scale of residential energy demand reductions achievable under decarbonization pathways, highlighting the importance of how buildings are used alongside what is built in bringing the sector closer to deep decarbonization while maintaining household well-being.