A large number of homes are not fully benefiting from the government's energy efficiency scheme to help them reduce bills from energy suppliers, it has emerged.
Experts say that double counting means that up to 9.8 million tonnes of carbon dioxide the carbon emission reduction target (Cert) is supposed to have saved is "illusory", reports the Observer.
According to Ofgem, around one million homes were fitted with loft insulation by professionals at the end of September but a further 38 million square metres, covering 969,000 homes, were insulted on a DIY basis by the end of December.
A number of industry sources said many professional installers bought material from retailers which are only supposed to be sold to homeowners.
This means that where professionals fitted homes with subsidised materials, energy suppliers are counting one address as having been insulated twice; once under the DIY category and once by professionals.
The Observer contacted six of the major energy suppliers - British Gas, npower, Scottish and Southern Energy, EDF Energy, E.ON and Scottish Power - and found that none could say how they prevented double-counting before Cert was introduced.
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