Energy Performance Certificates must change to properly support reaching net zero, tackling fuel poverty and improving buildings, according to an energy assessors accreditation scheme.

And it wants EPCs to be renewed every three years at most, with assessors central to a range of activities.

Elmhurst Energy, in an almanac published this month, makes policy recommendations including:

Redesigning the EPC to include the ‘Three Cs’ of energy consumption, energy cost and carbon emissions;

Using the ‘Golden Triangle’ for EPCs – Provide the building’s predicted energy cost and consumption of a building based on average occupancy, its occupancy rating based on the people using it, and its energy consumption;

Ensuring EPCs reflect the current state of a building – Reassess and reissue an EPC every time a building undergoes changes that impact energy performance, with no EPC older than three years;

Making energy efficiency education a priority – using energy assessors to provide consumer energy efficient living education;

Keep updating assessment methodologies –to reflect the introduction of new technologies and innovation.

In addition, Elmhurst is calling for the increased use of qualified energy assessors to help advise homeowners and businesses to boost the uptake of available renewable technologies; rebalance the tax applied to fuels to favour low emission fuels instead of fossil fuels; use available technology to measure real-time building energy consumption and heat loss; and create a national standard for Net Zero buildings, including introducing an independent certification or competent persons scheme. 

Elmhurst Energy managing director Stuart Fairlie says: “Against a backdrop of rising fuel poverty, environmental pressures and energy security concerns, EPCs are coming in for a lot of scrutiny and criticism. This is understandable, as the EPC as it exists now is over 15 years old. It was designed then simply as a cost metric, showing how expensive or cheap a home is to run.

“This is now too basic a measure for the challenges we face today. People care about cost, energy consumption and carbon emissions. 

The time is now right to update the EPC so that it can more easily communicate vital information about the predicted and actual energy use and carbon emissions of a building.”

EPCs – for some years the subject of criticism by many in the property industry – took a particular battering last month when the Sunday Times revealed the results of sophisticated and highly detailed research by a firm called CarbonLaces. 

The firm claims EPCs overestimate energy use by up to 344 per cent – yet they remain a key part of current and expected legislation affecting landlords and other home owners.

CarbonLaces compared the EPCs of more than 17,000 homes with their actual use, as logged by smart meters every half hour for at least 300 days, to calculate their energy bills. 

The Sunday Times reports: “The average metered gas and electricity use for all the properties studied was 125kWh per square metre a year — 91 per cent lower than what their EPCs claim (239kWh/m2/yr).

“The lower the EPC rating, the bigger the overestimation. For properties with the worst rating of G, EPCs estimate they use 656kWh/m2/yr. Yet their smart meters show they use only 151kWh/m2/yr — a 344 per cent gap.”

This inaccuracy is “quite staggering” says Madhuban Kumar, the founder of CarbonLaces. 

She says EPCs overestimate not only energy use but also carbon emissions, by between 20 per cent (for EPCs rated C) and 308 per cent (for EPCs rates G). 

The lengthy Sunday Times report also claims that EPCs on new build homes are open to widespread abuse.

For new homes, EPCs can be issued on design data alone. The [design] software assumes everything is perfectly fitted, but this may not always be the case.

The paper cites an example of workers on a new home “going around the skirting boards, sealing it all with mastic and foam.” He then had to rerun tests until the home passed — only for carpet fitters to cut out all the sealant again.”

This issue is of critical importance to the lettings industry because the government has pledged to reduce energy consumption from buildings and industry 15 per cent by 2030, with aspirations for properties to have a minimum EPC rating of C in England and Wales by April 2025.

Under current government regulation, landlords are not expected to spend more than £3,500 on upgrades to meet the current EPC requirements for a rating of E. 

However, proposed changes could see all rental properties requiring an EPC rating of C by 2028, and a potential increase to this cap to £10,000, meaning landlords could be required to spend more to meet minimum requirements.