Your browser is no longer supported

For the best possible experience using our website we recommend you upgrade to a newer version or another browser.

Your browser appears to have cookies disabled. For the best experience of this website, please enable cookies in your browser

We'll assume we have your consent to use cookies, for example so you won't need to log in each time you visit our site.
Learn more

Action taken on EPC software glitches

The Government has been warned to sort out the software underpinning energy performance certificates quickly or see its efforts to promote energy efficiency permanently undermined.

The Department of Communities and Local Government has admitted it is carrying out a review of the Reduced Data Standard Assessment Procedure (RDSAP) software, after some properties were incorrectly assessed.

RDSAP is used to calculate an energy rating for a home. The software takes into account a wide range of factors in a property, including the age and dimensions of the property, the material used to construct the dwelling and whether double glazing has been installed.

To keep the costs of certification down, the software used to generate certificates had been developed to be simple enough to achieve consistency with a limited amount of time spent on site by the energy assessor. 

A department spokesman said: “Since August 2007, more than a quarter of a million EPCs have been produced using this software and the accuracy of the vast majority of these has been within acceptable limits. 

“It is however early days and it is becoming apparent that for a small number of properties this approach needs some refinement. 

“We will therefore be carrying out a review of the methodology and software with a view to enabling a more sensitive tool with additional data input to be used where this is considered appropriate by the accredited energy assessor. “

Deputy Managing Director at National Energy Services, Austin Baggett, one of the companies which has noted issues with the software, said in 99 per cent of cases the software was effective, but he added:


“We and others are working with the Government to enhance RDSAP in the field to make it better able to cope with buildings which have been built outside the norms.


“We hope that changes will be in place by October this year. However, at the moment RDSAP is more than adequate, in terms of accuracy, for the vast majority of houses.”

Mike Malina from Energy Solutions Associates said: “It doesn’t surprise me. They need to get their act together and get this working properly. Any glitch will undermine the system.

“But you do not want to make it too complicated – you need a system which works. I just hope they put the resources in they need to.

Mr Malina said one of his key concerns was the Government needed to start enforcing regulations on building efficiency which were already in place.