A systemic decision-making model for energy retrofits

In most European countries, the energy retrofit dynamics remain too low to meet the climate mitigation goals, despite all existing policies. While the literature is rich in articles about barriers to energy retrofit, little is known about the systemic reasons why homeowners decide against it. The complex decision-making process of homeowners involving energy retrofits is analysed by combining psychology and complexity science modelling. The psychological Rubicon model serves as the conceptual basis for developing a qualitative complex system model (Causal Loop Diagram—CLD) that describes the interdependencies between individual decision-making (including bounded rationality) and societal influences. The systemic decision-making model reveals that especially media and word-of-mouth effects in the social environment have a remarkable impact on the perceived social norm about energy retrofit of homeowners and thus their decision. While all reinforcing feedback loops are located within the motivation phase of homeowners, the balancing ones are identified in the detailed planning, realisation and evaluation phase. Based on the model findings, three levers are derived, which policy mixes need to address to foster energy retrofit. The applied approach of combining psychology and complexity science seems promising for future policy advice in complex transformational processes. Policy relevance This systemic decision-making model provides complexity-informed policy advice for improving the engagement and motivation of homeowners in their energy retrofit decisions. Three general leverages are derived that policy mixes need to consider to enhance the decision of homeowners for energy retrofit: (1) raising enthusiasm and trust for energy retrofit within the society; (2) shifting the perception of ‘own benefits’ relative to ‘own efforts’ for homeowners to be more advantageous; and (3) reducing the bottleneck of insufficient capacity of specialist workers/contractors, planners, energy consultants and energy retrofit material. Currently, point (1) is seen as the largest leverage for motivating more homeowners by a positive societal debate, reducing uncertainty and perceived overload. For each leverage innovative policy, suggestions derived from the model and literature review are proposed for each aim.