Effects of building fabric requirements on willingness to adopt a heat pump

Decarbonising residential heating requires widespread adoption of heat pumps, yet uptake remains below policy targets. Low uptake may be partly explained by building fabric upgrades that current policy assumes heat pumps require to work efficiently, but the effect of these upgrades on heat pump adoption remains underexplored. This study examines how such requirements influence homeowners’ willingness to adopt heat pumps using a pre-registered survey experiment with a nationally representative sample of homeowners in Ireland (n = 574). Participants reported their intentions to adopt a heat pump as they received sequential information on its benefits, installation costs, and personalised upgrade requirements for their own home. Information on benefits significantly increased willingness to adopt, but this effect was fully reversed once participants learned about required building fabric upgrades. Wall insulation in particular had a large deterrent effect, with a marginal reduction in adoption intention of approximately 40% compared to only ventilation upgrades (19.7% vs. 11.6%). An embedded survey experiment testing an enhanced heat pump installation grant substantially increased willingness at the point of cost information, but this effect was largely eroded after upgrade requirements were introduced. Additional interventions, including cost comparisons and information on low-cost financing, had no meaningful impact. The results demonstrate that adoption decisions depend on the full set of costs and requirements associated with heat pump installation. Forecasts that fail to recognise the deterrent effects of these requirements are likely to overestimate heat pump uptake. Policies that subsidise heat pumps alone are unlikely to achieve target uptake where significant preparatory works are required.