Already done. New building regulations, Part O, which came into effect in June last year, set out rules on overheating. Those regs impact the minimum amount of

Already done. New building regulations, Part O, which came into effect in June last year, set out rules on overheating. Those regs impact the minimum amount of insulation required in new homes while ensuring they're designed to prevent overheating in summer. Keep in mind that prior to that, Part L stipulated that loft insulation had to be at least 270mm thick. That's specifically for mineral wool and similar roll style insulation which is the most common option. PIR on the other hand wouldn't have to be as thick to meet the same performance criteria.