Home insulation promoted by the government may end up killing old people in their homes, apparently (hat-tip to Chris Snowdon ):
Prof Chris Goodier, of Loughborough University's department of civil and building engineering, said it was vital that homes in the UK better insulated to help meet carbon emission targets and save on winter fuel bills.
But he said the risk of overheating had been overlooked in the "big rush to insulate and make homes airtight", particularly as more extreme weather events, including heatwaves, are being predicted for the UK by meteorologists.
"Overheating is like the little boy at the back of the class waving his hand. It is forgotten about because the other challenges are so big,"
This is nothing to sniff about. Back in 2003, a staggering 70,000 people died  in heat-related deaths during a Europe-wide heatwave, partially caused by elderly people living in homes designed to withstand cold winters instead of extremely hot summers.
That heatwave was widely attributed to global warming, which the 'Green Deal' home insulation is meant to stop. But this sort of unintended consequence shows the danger of imposing any one 'solution' to problems in complex systems. If the 'solution' causes problems of its own, those problems will be compounded across a much wider area than if different 'solutions' had been allowed to emerge from the bottom up.
Where there are collective action problems like global warming, the simple solutions that adjust incentives and let the market try lots of little things out (like carbon taxes ) beat the grand plans of Very Clever People who cannot possibly know the full consequences of their actions. Of course, even things like carbon taxes may have their own unintended consequences too .