More than one in ten landlords (14.5%) say that some or all properties in their portfolio fall into the bottom Energy Performance Certificate categories, with an F or G rating.
The finding, which emerged in a survey of 1,500 landlords by the Association of Residential Letting Agents, could mean a sharp reduction in the supply of rental properties.
From 2018, properties with low EPC ratings – likely to be anything below E – will be banned from the rental market.
The same ARLA survey also showed that more than one third of landlords (36%) do not know the energy rating of their properties.
Alan Ward, chairman of the Residential Landlords Association, called for the Landlord’s Energy Saving Allowance – an annual tax allowance – to be raised from £1,500 to £14,000. The allowance is due to be scrapped altogether in April 2015.