Guardian: Generations of undemanding construction standards and poor building techniques have left our homes among the worst insulated in the developed world with an average heating bill of £600 and emissions of almost three tonnes of carbon dioxide. Cutting our domestic heating bills is a good way to reduce our carbon footprints and spend the fiscal stimulus here and in the US. But bringing our housing stock up to 21st-century standards is a hugely expensive task involving major changes to the way …