Fears that 100,000 homes could have been given incorrect energy efficiency ratings have been raised by the Residential Landlords Association.
New figures from the Building Research Establishment have shown that Energy Performance Certificates can understate the energy efficiency of homes with solid walls and uninsulated cavity walls.
The BRE claims that 100,000 properties have been given incorrect F and G classifications – the lowest ratings possible.
The RLA is now campaigning for greater accuracy when it comes to allocating the ratings and is in talks with the Government over the issue.
The news comes as the Government has given a target date for energy efficiency compliance in rental properties.
By April 2018 it will be unlawful to let out a property with an F or G Energy Performance Certificate (EPC) rating, i.e. a new let, although there will be some limited exemptions.
It is understood the Government then hopes to introduce a minimum E rating , not just to new lets but also to existing tenancies, with plans to introduce a minimum C rating moving forward over the next 15 years.
Richard Jones, policy adviser and company secretary said: “At the RLA we have major concerns around the accuracy of EPCs, particularly as these form the basis for the new compulsion requirements imposing a minimum E banding from 2018 onwards, starting with new lets and moving onto existing lets.
“The BRE estimates that around 100,000 properties have an incorrect F and G rating so these ratings should be better than they are.
“This means some of those currently rated at the lowest banding Band G ought to be reclassified as Band F and quite a number of those that are in Band F do in fact meet the Band E requirement.
“We are making repeated representations to the Government on this issue because we firmly believe that EPCs must be accurate before compulsion is brought in.”
Mr Jones said that landlords need to look to the future to establish the best way of implementing improvements.
He said: “If you carry out improvements piece by piece, going first to Band E and then subsequently Band D and then onto Band C a different approach is required than if you carry out a whole house improvement to go straight to Band C from the outset.
“In the past the RLA has commissioned research to help landlords and is going to undertake further investigations once the accuracy of the EPCs issue is satisfactorily resolved.
“Energy efficiency in the private rented sector is very much in the Government’s sights at the moment and the RLA will keep our members up dated with any further developments on the issue.”