Homeowners may soon get a surprise as councils plan to send “energy police” into suburbs to test their heat insulation.
At least 25 councils are planning to use heat detector vans to take thermal images of homes, in a bid to encourage residents to become more energy efficient.
The vans creep along at 10mph, unbeknown to those indoors, and survey a thousand homes an hour.
The result is a thermo image of each house, pinpointing the heat escaping from leaky doors, windows, walls and lofts.
Once the houses are photographed, images are given to homeowners to show them where energy is being wasted.
Energy and Climate Change Secretary Ed Miliband welcomes the new approach, as he believes the ultimate solution lies in going door to door.
He said: “It’s been experimented on by a few councils and what we want to see is… can this be taken wider and more nationwide?