Switch mobile phone chargers off at the socket. Unless you do this, your charger will continue to work even when it's not actually charging up a phone. You can tell it's using electricity because it'll be warm. Across the UK, mobile phone chargers left plugged in waste electricity worth over '60 million.

Switch off your computer when you go home. The cost of leaving a typical PC on every night for a year is around '50. Tens of thousands of computers are left on overnight in UK offices, schools, and workplaces, costing millions and generating hundreds of tonnes of CO2.

Water coolers and water heaters should be switched off overnight and at weekends. They use a lot of electricity, so running them when the office or workplace is empty is a waste of money. Timers can be fitted so that they come on and go off automatically. There are no health reasons why water heaters can't be switched off at weekends; harmful bacteria will be killed by the boiling.

Keep the warmth in the areas where it's wanted. Certain parts of buildings - e.g. foyers, storerooms corridors - don't need to be kept as warm as others. The trick is to keep the warm air where it is needed, and prevent it escaping into areas where it isn't. Modern heating systems can heat various parts of a building differently, and shutting doors will also help.

Fans and other air-coolers offer relief at the click of a switch, but they're an expensive way to keep cool. If possible, it is better to take action to stop the room overheating in the first place. Closing window blinds - and turning off unused computers, lights and other appliances - will help prevent a workplace from becoming uncomfortably warm.

Switch off lights when they're not in use. Individual desk lamps are likely to be energy savers if they are used instead of overhead lighting, but they should still be turned off when you leave your desk - even if only for a few minutes. Lights also give off heat, and in summer the combined output of several desk lamps and computers can make a room feel uncomfortably warm.

If water is scalding at the tap then it is being stored at too high a temperature. This could be wasting large amounts of gas or electricity, not to mention money. If this is the case in your home, turn the thermostat on your hot-water tank down to 60°C (140°F), or adjust the setting on your gas boiler.

Before you install, think energy. Electronic notice boards like this one don't use much electricity, but in many cases they can't be switched off manually and are left on for their whole working lives - even when there is no one around to read the message.

Only fill the kettle with as much water as you need. The more water you boil, the more energy it takes. If everyone boiled only the water they needed, we would save enough electricity in a year to run nearly half of the UK's street lighting.

Only light rooms or parts of rooms that are being used. Certain areas must be lit at all times for safety reasons, but there are parts of many workplaces where lights can be safely switched off when not needed. Is natural daylight enough?

When you can, switch off at the source. Most office equipment can be safely turned off at the socket - if in doubt, ask your energy or facilities manager. In the home, TVs, CD players and other appliances left on stand-by account for around 10% of many household's electricity bill - '50.00 on average.

Switch off your monitor when you leave your desk - even just for 20 minutes. Nearly 70% of the energy consumption of a computer is the monitor, so turn it off when you're not using it. A PC monitor left on overnight uses enough energy to microwave six dinners.

Switch off office equipment when it's not in use. The UK's nearly 1 million photocopiers are full of bright lights, lots of moving parts, some extremely hot elements and fans to cool down. They consume large amounts of electricity, even when they're just sitting there. A timer on the plug would mean they could come on in the morning and go off in the evening and weekends automatically.

Last one out of the office; switch off the printer(s). There are 750,000 laser printers in the UK, and if even a small percentage are left running overnight this represents a lot of wasted electricity. And remember to ‘think before you print' as every page you print uses energy.

Can the heating in your workplace or office be smarter? Most workplaces' heating/ cooling systems are not ideal, but we can do our bit by dressing appropriately. This may mean shedding that jacket and tie in summer, or adding a layer in winter.

Heating system set too high? Don't open a window, turn down the radiator. And in winter, a badly sealed window allows heat to escape and can make a room feel cold and draughty. If cold air whistles through your windows at work, report it; if it happens at home, get your windows fixed.