The Carbon Trust provides advice to business on the ways to reduce energy consumption and the carbon footprint:

Monitor your energy

Metering and monitoring are at the heart of energy management. With metering, you can account for costs, assess performance and quickly spot the cause of expensive problems, such as faulty or ageing equipment. An additional word of caution from the Carbon Trust is that ‘Energy bills can often be estimated, so don’t rely on them for accuracy.’

Heating

In the commercial sector, heating comprises more than half of all energy consumed. If the capacity of your heating and hot water system is more than 20kW and it is more than 15 years old, DCLG recommend that you get a competent heating engineer to assess it.

Also, you should take a look at the DCLG publication- ‘A guide for businesses- Reducing the energy usage and carbon emissions from your heating and hot water systems' - available for  download 813.60 Kb.

Don’t turn up the heating unless you really need to. Unless it’s just too cold for comfort, try to keep your thermostat at 19°C. Your heating costs will go up by 8% each time you increase the temperature by just one degree

Lighting

Switch lights off in empty rooms. You could cut your lighting costs by as much as 15%, just by making sure you turn lights off in rooms and corridors that aren’t being used.

Don’t use more light than you need. If you’re only working in one part of the room, why have all the lights on? Don’t strain your eyes, but try not to use more light than you need.

Make the most of natural light. It’s free and it won’t damage the environment. So keep your windows clear, and make the most of the daylight.