Wouldn't it be easier for the Scottish Executive to toughen Scotland's building regulations so that completion certificates depended on passing air tightness tests?

BBC: The ?1,000-a-year heating bill is here.

The 12, 700-square-foot Energy Star-certified house was crafted from low-toxic materials, withstood air tightness tests on the insulation, and has a water furnace geothermal system that provides hot water, radiant floor heat and air conditioning.

FORBES: Off-The-Grid Mansions

Though mandatory air tightness tests are not.

BBC: The ?1,000-a-year heating bill is here.