To meet EU climate goals, reducing fossil fuel use is crucial, and transitioning domestic energy consumption to sustainable sources like heat pumps offers a potential solution. However, uptake in Flanders remains low. This study explores predictors of heat pump adoption intention among Flemish homeowners using a mixed-methods approach. A quantitative survey based on an extended Theory of Planned Behaviour model (Study 1, n = 692, M_age = 55.03, SD_age = 15.54, male/female = 335/357) is complemented by semi-structured interviews with homeowners who do not own a heat pump (Study 2, n = 16, M_age = 41, SD_age = 35, male/female = 8/8). Study 1 indicates that perceived behavioural control and subjective norms positively influence heat pump adoption intention, with perceived behavioural control enhanced by product knowledge and technological innovativeness. Surprisingly, a positive attitude towards heat pumps is associated with a lower adoption intention. Study 2 reveals cost concerns, uncertainties about energy cost savings and property value increases as barriers to adoption intention, alongside a temporal disconnect between attitude and intention due to practical constraints. Our findings offer suggestions for communication strategies of policy makers such as addressing financial and practical barriers, mitigating practical constraints and enhancing public knowledge. Lastly, our survey results suggest the presence of yet unidentified moderating variables affecting the attitude-intention relationship, which could be determined in future research.

Since heating-related energy consumption is one of the main sources of greenhouse gas emissions and accounts for a large part of domestic energy use in Europe, reducing heating-related energy consumption has great potential to reduce Europe’s greenhouse gas emissions. This study examines which factors determine people's intention to decrease heating-related energy usage, specifically lowering the temperature in winter. It was part of a larger European project focused on promoting energy reduction. This study presents a smaller-scale model tested among 363 individuals from five pilot countries, i.e., Belgium (n = 58), Croatia (n = 82), Germany (n = 105), Greece (n = 33), and Portugal (n = 85). We applied three robust theoretical frameworks: the Theory of Planned Behaviour, the Value Belief Norm Theory, and the Prototype Willingness Model. We conducted a confirmatory factor analysis to ensure construct validity, followed by a structural equation model. Our findings suggest that willingness (from the Prototype Willingness Model) is the most important predictor in explaining someone’s intention to reduce heating-related energy consumption. Additionally, perceived behavioural control, subjective norms, and attitudes (part of Theory of Planned Behaviour) also play an important role in predicting the intention to reduce energy consumption. Lastly, personal moral norms (from the Value Belief Norm Theory) have a significant impact, but their effect is moderate compared to the other predictors.