People all over the country are missing out on potential savings on their utilities bills, Consumer Focus has warned.
There are all sorts of steps that can be taken, including making improvements to insulation and checking that the best tariff or payment method is used.
Two-thirds of those questioned by the organisation said they are not fully confident that their home is as energy-efficient as it could be, with seven out of ten not planning on doing anything about it.
Furthermore, 47 per cent of respondents didn't know how thick the insulation in their loft is, meaning they are unaware of whether or not it needs to be improved.
Mike O'Connor, chief executive of Consumer Focus, said: "Many people are paying more than they need to because their home is leaking heat and they aren't on the cheapest deal."
He added that people tend not to realise that energy companies will often provide free or discounted insulation.