Prosumer households can play a pivotal role in advancing energy sufficiency, but their behaviours are shaped not only by individual motivation,s but also by macro-level factors such as policy mixes and the availability of specific technologies and business models. This structure–agency nexus becomes particularly apparent in the integration of decentralized energy sources, the reduction of overall demand, and the adoption of flexible consumption practices. Flexibility can be offered by electric vehicles (EVs), heat pumps, and storage batteries, but fully exploiting the technologies environmental benefits requires adaptations in household consumer behaviour. However, energy models have so far focused on the adoption of single technologies in isolation, overlooking the interaction between individual preferences and contextual conditions. The present study addresses this gap by examining pathways towards energy self-sufficiency in prosumer households through co-adoption as well as flexible use of photovoltaic (PV) panels, EVs, heat pumps, and storage systems under different policy mixes. Using an agent-based model informed by discrete choice experiments with 1469 Swiss participants and a prosumer household energy flow model, we assess the impacts of individual motivations, policy mixes, and technology combinations on energy self-sufficiency from 2022 to 2050. Our findings reveal that environmentally motivated prosumers are more likely to adopt flexible practices, which in turn enhances long-term self-sufficiency. In contrast, financial incentives alone may drive adoption without supporting sustainable usage practices. The results show that while flexible technologies are increasingly adopted over time, their relative share diminishes. Early adopters provide energy flexibility by combining PV systems with EVs, heat pumps, home storage, and smart energy systems, whereas later adopters are less inclined to adopt this setup. These findings underscore the importance of policies that incentivize not only technology adoption, but also flexible usage to increase household self-sufficiency over time.