The UK Government has recently run a consultation on reform of Energy Performance Certificates (EPCs). National Retrofit Hub has shared its response and we broadly agree with it. We wanted to share our 3 key thoughts on the proposals, including why we continue to shout about the importance of measuring real-world performance to achieving the UK's net-zero goals.
Possibly the biggest proposed change that most people will see is to move away from a single metric/score to have multiple metrics. This is a good thing. The EPC rating is the biggest single problem with EPCs as it is widely misunderstood and misused.
For example, the Social Housing Decarbonisation Fund used EPC C as its minimum requirement, despite the EPC rating having nothing to do with carbon. Now the scheme has been renamed to Warmer Homes: Social Housing Fund, which has the same minimum EPC C requirement, despite the EPC rating having nothing (directly) to do with heating.
The new EPCs will have a number of different metrics (to be decided), but likely to include: cost, carbon, fabric efficiency, heating system and “smart readiness”. This clearer labelling will force policy makers to choose the appropriate metric for the outcomes they want to achieve rather than trying to use a single metric most people don’t understand for everything.
We have also recommended that government produces guidance aimed at policymakers to help them understand the metrics and where it is appropriate to use them.
Real-world energy performance is not addressed in the proposals, which is a missed opportunity. Incorporating real-world performance into EPCs could greatly improve their accuracy. Currently, airtightness is measured and included in EPCs for new builds, providing a clearer picture of a property's heating needs, so this could also be applied to existing buildings.
Additionally, U-values could be adjusted based on actual data rather than assumptions. This could be useful both before and after retrofitting, offering a more precise understanding of a building's performance. Lastly, the Heat Transfer coefficient (HTC) could also be modified based on measured data, i.e. via SMETERS technologies.
Real-world performance data can also manage expectations about energy savings. Existing homes often perform better than expected with measured data, while post-retrofit models may not always meet idealised performance levels. This is crucial for policymakers to consider when funding retrofit measures, ensuring investments lead to desired outcomes in terms of carbon emissions and climate change mitigation. It would also be helpful for comfort-as-a-service or heat-as-as-a-service business models, reducing the risk that householder costs increase.
The other main concern about EPCs is the quality of the assessment. EPCs can be wildly inaccurate and vary considerably for assessments done by different assessor on the same property (even where no changes to the property have been made).
For organisations using EPC data to develop large-scale retrofit programmes and plan property improvements, this is a big problem. The consultation proposes changes to improve assessor training and increase enforcement, but we feel the problem is deeper. The issue is that most assessments are done to tick a box – either because the owner is selling/renting the property, or because a social landlord has to demonstrate compliance with grant terms. Because of this, there is a race to the bottom in terms of cost and little attention is paid to quality.
What we need to do, and government needs to embed into policy, is recognise the value of the data being collected. The data collected during an EPC assessment should be seen as the first step in the process of improving properties to meet our fuel poverty and carbon targets, giving valuable insight into what measures the property needs to achieve those goals.
