This is even more important for a small business employing a few people and having fewer economies of scale. You may be based in some older offices that have radiators and a basic gas or oil fired central heating system. Say your heating bill is £5,000: if you put in a new condensing type boiler this will improve your fuel usage by 10%, saving £500 per annum. The cost of putting in the new boiler is £1,500 for the boiler and another £500 for it to be fitted. The total cost is £2,000, which means it will take about four years to get your money back.