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Consumer watchdog warns Energy Performance Certificates are unreliable and in desperate need of reform

Posted 25/06/2024 by Robyn Hall
Categories: General
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Which? Is calling for the next government to reform Energy Performance Certificates (EPCs) as a snapshot investigation by the consumer champion revealed they can be riddled with inaccuracies and unhelpful advice that could cost homeowners when they come to sell or make home improvements.

We’ve explained before how EPCs were introduced in 2007 as a simple way for prospective buyers or renters to compare properties’ energy efficiency.

The UK is currently facing a big challenge to reduce its energy use and switch to low carbon heating and for many households, EPCs will be the first step in getting advice on how to improve their home’s energy efficiency. Access to grant funding, or ‘green’ financial products such as loans or mortgages, is often available only to those who meet certain EPC-based criteria.

As part of its investigation Which? Contacted 12 members who were homeowners across England, Wales and Scotland and booked EPC assessments on their behalf during February to March 2024 to find out how accurate EPCs are. Their properties were built between 1650 and 1999 and ranged from a one-bedroom flat to a five-bedroom detached house.


Which? uncovered issues with the accuracy of the results and the recommendations that homeowners received.

One homeowner had their EPC survey done, but never received their certificate. The survey fee was refunded but the homeowner was left in the dark about their home's energy efficiency. Of the remaining 11 participants, just one was ‘very satisfied’ with their EPC and only three said they were likely to recommend getting an EPC, based on this experience.

Most participants (eight out of 11) told Which? their EPC did not appear to be accurate - they said the descriptions of key aspects of their home like the windows, roofs and heating systems were incorrect.


Several participants also felt that the recommendations suggested were unaffordable. One consumer said that they felt draught proofing was overlooked in their EPC report despite their home having an open chimney and front door with single glazing.

As a result Which? is now calling for the next government to reform EPCs to make them a more reliable and useful tool for householders. As well as addressing concerns about the accuracy and reliability of EPCs, Which? believes the design and content of EPCs should be reformed to ensure it provides consumers with the information and advice they need. This should include information to help consumers prepare for the transition to low-carbon heating.


EPCs should also be made more interactive, so that consumers can input information so that the advice is more relevant to their circumstances. EPCs should also include up-to-date costings relevant to the type of property and provide links to any financial support and a database of installers belonging to government-certified schemes.

EPCs are based on assessments by Domestic Energy Assessors, who can qualify through several different accreditation schemes that provide online and in person training. The next government should also review auditing of EPCs and the training requirements for this role to ensure that assessors have the skills needed to complete reliable assessments.


Rocio Concha, Which? Director of Policy and Advocacy, says: “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.

“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.”



Peter and Carol Vermeulen in Aberdeenshire achieved a D rating for energy efficiency for their 1980s four-bedroom semi-detached bungalow in Aberdeenshire following their EPC assessment.

But on receipt of the EPC, however, they noticed several discrepancies. There was no mention of their solar PV or solar thermal panels, or of a wood-burning stove. The suspended floor was described as uninsulated, although they had discussed their underfloor insulation with the assessor during the survey and offered to open an inspection hatch so this could be checked.

Which? contacted the assessor to point out the mistakes. After checking his survey notes, he admitted that there were omissions (which he blamed on the software) and offered to supply a new EPC.

The assessor issued a new, corrected EPC, with an improved B rating for energy efficiency. A better EPC can make a big difference for owners, as it allows them to command a higher price if they choose to sell and may make the home more attractive to tenants. 


Megan Dobney also achieved a D rating for energy efficiency for her two-bedroom Victorian terraced house in London.

The EPC recommended several improvements, including internal or external wall insulation (typically costing £4,000 to £14,000 and saving £172 a year), suspended floor insulation (typically costing £800 to £1,200 and saving £70 a year,) solar water heating (typically costing £4,000 to £6,000 and saving £57 annually) and solar panels (typically costing £3,500 to £5,500 and saving £621 a year).

Installing all four could cost Megan up to £26,700 and she would only see the property rise by one band from D to C. She could save around £920 a year through installing all these energy efficiency measures - meaning it could take up to 29 years to recover the cost.

Megan says: “The recommended changes are extremely expensive, generally for small savings each year, and would require massive disruption.”

With millions of families across the UK worried about high energy bills, EPCs could provide valuable information on how people can save money and improve their home's efficiency. However, they are in desperate need of reform.

Robyn Hall

UK Property and Finance Expert

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