Mayor says 10,000 homes could benefit from £9.5m cash for energy saving measures such as loft and cavity wall insulation

Residents in parts of nine London boroughs will be able to get a free whole-home “carbon makeover” under plans announced by Boris Johnson today.

As well as fitting energy efficient light bulbs and standby switches, the LDA will subsidise the installation of loft and cavity wall insulation for those who can pay and provide it free for those on benefits.

10,000 domestic properties could benefit from the £9.5m cash injection from the mayor and London Development Agency (LDA) which will go towards a trial.

With more cash, London agencies aim to reach all areas of London by 2012, with 200,000 homes benefiting from reduced energy usage by that date and 1.2 million having undergone retrofitting by 2015.

In order to roll out the scheme, the mayor, together with the LDA, London Councils, the Energy Saving Trust and London's boroughs are working to develop a single scheme that can be rolled out across the capital.

It is hoped that a single programme could attract millions of funding available from the government through the Carbon Emissions Reduction Target (CERT) scheme, which came into effect in April 2008, obliging electricity and gas suppliers in the UK to help reduce carbon emissions from homes.

The boroughs that will be running the trials are: Croydon, Camden, Lewisham, Harrow, Havering, Haringey, Hillingdon, Kingston, and Southwark.

Installing easy measures by 2015 could save 350,000 tonnes of CO2; more intense measures, such as loft insulation could save 1.2m tonnes, according to the mayor’s office.