British Gas is providing "up to 50,000 of Britain's most hard-pressed households" with free energy assessments and efficiency measures it says will help cut energy bills by £250 a year.
British Gas' home energy assessment is a full energy-efficiency survey of a home, which will receive a personalised and printed energy assessment including behavioural, energy efficiency and money-saving advice and an insulation survey.
Eligible households will also receive free insulation and other products such as electricity monitors and standby savers.
The company claims the initiative will be worth £10 million. Managing director, Phil Bentley, said: "Improving energy efficiency in our homes is the quickest way to cut our bills and lower carbon emissions. And this initiative will particularly help our most vulnerable and hard-pressed families."
British Gas will work with charities including National Energy Action, the Money Advice Trust and Scope as well as local MPs to ensure help is targeted where it is needed most.