Families argue about leaving the lights on in empty rooms more than once a week on average.
Half of all UK households (50%) argue about leaving the lights on, while homes with children under the age of 18 have a row about the habit 58 times a year on average, reveals research from Uswitch.com.
Although leaving the lights on causes the most arguments, it adds relatively little to bills. A 4.2W LED bulb left on for an additional four hours every day would add £1.75 to bills over a year.
Parents turn off 338 lights in empty rooms every year, although one in four children (24%) is helping to save energy around the home.
The cost of heating is the second most-common energy argument, with four in ten (44%) households falling out over it.
A quarter of households (25%) have rowed about the tumble dryer, while the same proportion have argued over how best to stack the dishwasher, with poorly-loaded crockery resulting in needing to run extra loads.
With the average dishwasher cycle using around 0.79kWh of energy, running the appliance for an unnecessary wash could cost households 23p each time. Similarly, a washing machine running on 0.712kWh per cycle could cost 20p for every extra use.
Nearly a fifth of households with children (18%) say their kids are better at saving energy than they were last year. One in ten parents (9%) with children aged five to 17 say that their children are the most committed people in the household when it comes to saving energy.
Natalie Mathie, energy expert at Uswitch.com, said: “The high cost of energy is causing friction in a lot of UK households, but everyone in the home can play a part in reducing their usage.
“Getting into good habits as a household can save a lot of money, and even small and simple changes such as turning off lights or TVs when not in use can all add up.
“While leaving a light on will cost very little over the course of a year, the cost of regularly running extra loads in the washing machine and dishwasher could set households back a few pounds every month.”
