Even a well-insulated, centrally-heated home can have its cold spots. For example, conservatories can be more difficult to heat than the rest of the house. For those chilly areas, a room heater can give you some added, localised warmth.
According to the Energy Saving Trust, "Electricity is currently the most expensive and carbon-intensive heating fuel available in the UK." Clearly then, it's important to choose wisely if you're thinking of adding an electric room heater. The following table gives you an idea of the heroes and villains - with their typical running costs per tariff.