Overfilling the kettle when making a cuppa costs every person over the age of 16 in Northern Ireland £1 a year, new research has found.
The Energy Saving Trust said households in Northern Ireland waste more than £11m a year by failing to take simple steps to improve their energy use.
Patrick Thompson, Operations Manager of the Energy Saving Trust in Northern Ireland, said small changes could add up.
"By making small changes in their daily routine, households here can save themselves millions of pounds - and prevent thousands of tonnes of CO2 escaping into the atmosphere," he said. "For example, leaving appliances on standby when not in use costs an unnecessary £8m ever year and overfilling the kettle costs £1.5m - but making small changes to routine can result in big savings.
"Even washing clothes at 30 degrees instead of higher temperatures could save us £2.2m per year."