Why an updated EPC is vital to hitting net zero

The past six months have seen a sharp rise in the number of government consultations on energy policy that require participation from across the construction industry. Policymakers are recognising the need to collaborate with specialists to improve the energy efficiency of domestic and commercial properties in the effort to meet net-zero carbon targets.

Many would argue that future policy must focus on renewable energy, electricity storage and grid management. However, this will be pointless if properties are still inadequately insulated and a high percentage of occupants are living in fuel poverty. 

The UK has some of the oldest buildings in Europe; many are poorly constructed and not fit for purpose. Future homes will need to be better insulated, adequately ventilated and less reliant on gas.

Given that existing properties represent so much embodied carbon, we cannot just demolish them and rebuild. So, we need a mechanism to compare them and recommend the most suitable improvements that reduce their carbon emissions and energy bills. Despite its flaws, the energy performance certificate (EPC) can do this – if its methodology is updated, as is likely according to the UK government's EPC action plan.

The construction industry and the government both recognise the need for EPC methodology to be revised to not only consider fuel cost as its main metric, but also look to use the other metrics available on the EPC such as environmental impact rating (carbon emissions) and primary energy. Doing so will not only make EPCs more accurate, but also ensure the public clearly understand what the certificates mean and respect their value.

The update must also reflect the move from domestic gas consumption to electricity, which will lower carbon emissions and primary energy use as efficiency improves. However, the transition will also see increased fuel costs associated with electricity on which the current Standard Assessment Procedure (SAP) rating is largely based and this is where the current issues lie.

At its heart, the calculation becomes a ratio between the total floor area of the property and the total fuel costs for the property. Therefore, the more you increase fuel costs, the more likely the SAP rating will go down. This means properties which use more expensive fuel such as electricity are likely to get a lower rating compared with mains gas, unless said electricity is served by renewables such as photovoltaics. Honest public engagement will be needed to explain the reasoning for this change, and show that it will better reflect energy usage in our buildings.

These changes would affect the way our properties are measured and result in a more accurate assessment that is fit for future policy usage. It would also ensure that homeowners and tenants are more engaged, and therefore more likely to make improvements of their own accord.

Stakeholder engagement and education can also be improved. The new central EPC register has a plethora of open data available to consumers and professionals. This could be used more positively, perhaps to help local authorities determine how they can make more localised improvements, and motivate them to hit targets early in a cost-effective way.

The possibilities for a more accurate and representative EPC are vast. But the message is clear: they remain a key player in improving the energy efficiency of buildings. By working across the industry, educating the general public about their usefulness, we can all take the steps required to achieve net-zero carbon emissions while also reducing fuel poverty.