Heating system decarbonization decisions in homeowner associations: a Bayesian learning agent-based model

Decarbonizing shared heating systems in multi-owned apartment buildings requires collective decisions under uncertainty, in which heterogeneous households repeatedly evaluate the proposal across multiple meetings before a supermajority can pass. This paper develops a stylized agent-based framework of repeated voting in homeowner associations (HOAs / VvEs), in which households parameterized using latent-class discrete-choice estimates update beliefs about heating-system attributes through Bayesian updating with heuristic signal construction. The framework is demonstrated through a Dutch VvE setting comparing a baseline repeated-voting process with a board-mediated information architecture that combines trusted information hubs, intensified information sharing, lower hub uncertainty, and central network position. Across 100 Monte Carlo runs, the board-mediated setting reaches the 70% supermajority threshold in 70 of 100 runs versus 50 of 100 in the baseline, with mean approval rising from 63.2% to 69.0%. A component decomposition shows that the effect arises from the joint operation of the four board components rather than from any individual component. A vote-switching diagnostic based on conditional transition probabilities shows that the board-mediated architecture makes votes stickier in both directions, opponents convert less and supporters defect less, with the reduction in supporter defection robustly the larger of the two. The architecture therefore raises attainment by reducing decision volatility, with a robust supporter-stabilization component, rather than by converting entrenched opponents. The paper contributes a transparent computational framework for studying how heterogeneous preferences, belief updating, and trusted information channels jointly shape repeated collective decisions, and a testable hypothesis: a board-mediated information architecture raises supermajority attainment by reducing decision volatility and accelerating convergence, and stabilizing the pivotal, uncertainty-sensitive household class rather than converting entrenched opponents.