>Bearing in mind how much profit a lot of home builders make, increasing the regulations is likely to add at least £20K to a basic house, significantly more if you include mechanical ventilation, triple-glazed windows and heat pumps (perhaps +£50K), which is some cases will be 50%+ of the original cost!
The sales price of houses in the UK (and elsewhere) is driven by the market and there is a low amount of released, buildable land and a lot of demand in the Southeast. The land value (a large component of the value) is not actually set in an independent market but is based on the expected sales price minus construction costs and development costs. Therefore increasing the built cost of properties will decrease the value of land likely to receive planning permission without affecting purchase price by much.
The marginal cost of thicker walls is also very low (especially compared to retrofit costs) so the impact on construction cost is nothing like £50k.
The sales price of houses in the UK (and elsewhere) is driven by the market and there is a low amount of released, buildable land and a lot of demand in the Southeast. The land value (a large component of the value) is not actually set in an independent market but is based on the expected sales price minus construction costs and development costs. Therefore increasing the built cost of properties will decrease the value of land likely to receive planning permission without affecting purchase price by much.
The marginal cost of thicker walls is also very low (especially compared to retrofit costs) so the impact on construction cost is nothing like £50k.