Beyond efficiency: Sufficiency unlocks deep decarbonization of U.S. residential sector

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 unquantified in national energy system analyses. We quantify how structural sufficiency (dwelling size and housing form) and behavioral sufficiency (thermal comfort preferences via thermostat settings), alongside efficiency and electrification, contribute individually and in combination to emissions reductions. 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%. Sufficiency measures offer substantial mitigation potential, enabling deep decarbonization while maintaining household well-being.