What exactly causes the emergence of the attitude-behaviour gap, and to what extent, is not fully understood. Previous academic research has shown that many barriers to adoption remain, and that difficulty lies in the heterogeneity of consumers. Through the use of a simulation model this thesis explores the emergence of the attitude-behaviour gap by analyzing the decision-making behaviour of heterogenous Dutch households, parametrized by real-world survey data. Ultimately, to close the gap by lowering the barriers to adoption with policy interventions. An agent-based simulation model (ABM) has been developed to address the main research question: To which extent can different psychological factors influence the emergence of the attitude-behaviour gap in household energy consumption, and what policy interventions can be employed to close the gap?