It's something we'll all have been guilty of - leaving the light on. After all, it won't cost you that much...right?
A study conducted by Utility Design has revealed a staggering 10 per cent of us (6.5 million) have admitted to leaving the light on once we’ve left the room - and it ends up costing an extra £2.30 per user, or in total, £14,950,000 of wasted energy each day.
When you consider it from a personal finance angle, and base it on the average sized household, the cost of one person regularly leaving lights on can rapidly rise - it adds up to over £16 a week, £64 a month and over £800 a year.
Equally astonishing, 21 per cent of us (an estimated 14 million) will then leave the lights on when going out - for instance, heading to work. This ends up costing £0.77 per user, adding up to £15.40 each month, and an unnecessary £184.80 a year.
It seems Brits also leave lights on while trying to sleep at night, with 4.7 million people admitting they would leave at least one light on when they went to bed. Over an average eight-hour period, this will be £3,619,000 spent each night across the country, working out as a very costly night light for us...
This costs each user an average of £23.42 each month, and users will end up spending £281.05 each year.
Leaving lights on is also having another unfortunate impact too - 67 per cent said it was the number one reason for rowing, followed by not doing the dishes (65%) and leaving clothes or shoes on the floor (62%).
The main room we'll forget to turn the light off in is the bathroom - this will result in costs of around £64.51 each month.
Interestingly, when we set off on holiday, 43 per cent of us leave a light on - however, while this may deter burglars, we don't consider the impact this could have. It will normally be the hallway light that is left on - over a two-week spell, this ends up costing an average of £32.26.