In a well-insulated building the energy emitted by a television, a fridge and two human bodies would be enough to heat it, said senior electrical engineer Bill Watts, who thinks we could all save money and energy by adopting Passivhaus building standards. Although central heating systems would be needed on the coldest days, they would be made “all but redundant” in homes built according to Passivhaus standard, said Mr Watts, a senior partner at engineering firm Max Fordham. The standard, developed in Germany in the early 1990s, leads to homes that are so energy efficient they only need an extra 15kWh/sq m per year of heating energy. So, just an hour in front of the box would be “enough to keep you warm when it’s down to three degrees outside. That will give you 21 degrees inside,” said Mr Watts. “It does depend on whether you’ve got very heavy concrete walls. But if it’s a modern construction, things will heat up very quickly.” Mr Watts said those wishing to feel the full heating benefits of a television would need to thoroughly insulate their home through such methods as triple-glazing and wall insulation. “The average home in the UK uses 130kWh/sq m per year to heat. Even in older homes, effective insulation can, in some cases, reduce this to as little as 15kWh/sq m per year, meaning the modest amount of radiated heat from a television in a well-insulated home would keep most of us comfortably warm,” said Mr Watts. Although popular in Germany and Sweden, not enough homes in the UK are being built to the Passivhaus standard, he said. Instead money was being spent on more wasteful systems such as Combined Heat and Power schemes and District Heating, which are switched on all year round and can cost between £5,000 and £15,000 to install. Investing in Passivhaus standard insulation of existing building stock as a national infrastructure priority, would also reduce the need for new power plants. “Maybe we wouldn’t need that next generation of expensive Chinese-funded, French-built power stations after all,” he said.