The nature of the rental market at the moment means that landlords are not showing interest in improving the energy efficiency of their properties.

This is the view of private rental sector expert Malcolm Harrison.

Mr Harrison said that the "tremendous upsurge in demand for rental property at present" means that tenants are unable to "pick and choose" the qualities they want in their home.

However, he added that the "main problem is the shortage of rental stock".

The comments follow a post from the Residential Landlords Association which compiled figures suggesting that tenants are intent on becoming more energy efficient.

According to a release from Paragon Advance, average rental prices in London stood at £916.52 for the first quarter of 2010.

Paul Abbott, head of property and mortgages at the company said that prices remained high for "a number of reasons", including the high house price to earnings ratio and the current difficulties in obtaining high loan-to-value borrowing.