Consumer champion Which? is calling for a major overhaul of Energy Performance Certificates (EPCs) following an investigation that revealed widespread inaccuracies and unhelpful recommendations.
Introduced in 2007 to help landlords, homebuyers and renters compare a property's energy efficiency, EPCs are crucial for accessing grants and green financial products.
However, Which? found the system riddled with problems.
Its investigation involved EPC assessments on 12 properties across the UK.
Only one homeowner was satisfied, and eight reported inaccurate descriptions of key features like windows and heating systems.
EPCs in need of reform
Rocio Concha, Which? director of policy and advocacy, said: "With millions of families worried about high energy bills and the UK facing a big challenge to transition to low carbon heating, Energy Performance Certificates could be a helpful tool for consumers looking to save money and improve their home's efficiency in the future.
"However, our research shows they are in desperate need of reform - with current certificates often inaccurate and only suggesting costly improvements with long pay back periods."
She added: "The next government must make Energy Performance Certificates a more reliable and useful tool for householders.
"This should include reviewing the auditing and training requirements for Domestic Energy Assessors and ensuring EPCs provide relevant information and clear, actionable advice for consumers."
Recommendations by assessors were unrealistic
Many of the EPC recommendations being made by assessors were deemed unrealistic, with some homeowners feeling crucial energy-saving measures like draught-proofing were overlooked.
With energy bills a major concern for millions, Which? says that EPCs could be a valuable tool for homeowners and renters.
Which? is urging the next government to address the issues with EPCs, including improving assessor training and qualifications.
It also wants to see EPCs become more interactive, providing up-to-date costings and linking to relevant financial support and certified installers.
EPC did not appear to be accurate
Worryingly, eight of those taking part said their EPC did not appear to be accurate and pointed to inaccurate descriptions of windows, roofs and heating systems.
One said that their draught proofing had been ignored.
Several also said that the recommendations suggestions were unaffordable.
Which? also wants to see the design and content of EPCs to offer clear information and advice that consumers need.
There should also be up-to-date costings relevant to the property type and links to financial support - and installers that belong to government-certified schemes.
A government review should also look at the training of Domestic Energy Assessors to deliver accurate EPC assessments.
People's frustrations about the current EPC
In response, Stuart Fairlie, the managing director of Elmhurst Energy, said: "We share people's frustrations about the current EPC and have long campaigned for its reform.
"It's time EPCs changed to show energy cost, energy consumption and carbon emissions, as well as information on potential low carbon heating solutions and ways to improve the energy efficiency of their home."
He added: "We're disappointed to see the Which? EPC assessment results and can understand why homeowners might want information to be presented in a clearer way, with straightforward recommendations."
'EPCs in the PRS has been controversial for years'
The managing director of Accommodation for Students, Simon Thompson, said: "The issue of EPCs in the PRS has been controversial for years with lots of landlords struggling with the same issues highlighted here.
"A comprehensive EPC reform should help empower landlords to help tenants deal with high energy bills and make eco-friendly improvements.
"A more reliable and informative system would not only benefit landlords and tenants financially but also contribute to the UK's transition to low-carbon heating."
He added: "Landlords want to offer a quality home to tenants and knowing what the EPC is helpful - but there appears to be too much variance between what assessors find and what needs to be done.
"This reform should take place as quickly as possible."
