Household-level energy-saving behaviors help mitigate climate change within the broader energy transition. However, existing studies have primarily emphasized direct economic incentive interventions, with relatively little attention to energy-saving behaviors in the private sphere. This study examines the drivers of private-sphere energy efficiency behaviors in a non-Western context of residential buildings, focusing on social norms, awareness, and perceived personal responsibility in China. Building from previous assertions of social practice theory, we assess whether individuals feel personally responsible for building-related emissions and whether they view occupants as the primary agents to enact operational efficiency. Using an original survey dataset of 1,042 respondents in China, we analyze both ongoing behaviors, such as turning off lights and A/C, and one-off actions, including home energy efficiency upgrades. Hierarchical regression models sequentially examine the effects of demographics, social norms, awareness, and personal responsibility. Results indicate that social normative pressures and awareness predict engagement in energy efficiency behaviors, whereas perceptions of personal responsibility do not. These findings suggest that individuals adopt desirable efficiency behaviors even without strong sense of responsibility or self-efficacy motivation, highlighting the potential of leveraging normative influence and information campaigns to overcome behavioral barriers and advance decarbonization in the residential building sector.