The policy should be encouraging a fabric first approach to heating homes. All homes should be passivhaus standard. The additional costs of meeting this standard should not be considered standalone. By this I mean that not only should the costs of building the house to this standard be considered. Assuming the house is heated using electricity the incremental costs required to increase electricity generation and distribution capacity should be considered. In winter it is very unlikely that the electricity requirements can be met on site (e.g. solar). Off-shore wind, nuclear and other means of production will be required to generate the electricity which will entail substantial additional distribution infrastructure.
The cost of this additional generation and distribution infrastructure must be factored when considering the cost-benefit of a building’s insultation requirements.