A recent white paper sheds light on a little-known issue that could leave many landlords facing legal and financial repercussions. This comprehensive report delves into the reliability of area measurements used to calculate EPC ratings of residential properties. Conducted with market-leading Spec technology, the research scrutinized the property areas of 532 homes, comparing public EPC register data with Spec’s precise digital surveys. The findings are eye-opening and call for immediate attention from property owners.

The study reveals that a staggering 2,500,000 EPCs, approximately 15%, are inaccurately rated. These inaccuracies are not minor; they can result in significant shifts in a property’s EPC score, sometimes altering the rating altogether. Such discrepancies are not mere statistical anomalies but have tangible consequences. For instance, an estimated 35,028 properties currently rated as E are being let illegally. These properties have borderline EPC scores that, if measured accurately, would likely be downgraded to an F, making them non-compliant with rental regulations.

A critical finding of the report is that even a slight 1% change in property area can lead to a one-point change in the EPC score. This variability underscores the precarious nature of relying on current EPC measurements. More alarmingly, a 3% change in area can alter scores in two-thirds of the cases sampled. On average, the discrepancy in property area reported in EPCs was found to be 8.6% or 87 square feet. This margin of error indicates that most EPCs on the register are likely to have inaccurate scores, posing substantial risks to landlords.

One in four properties had area measurements on their EPCs that varied by at least 10% (100 square feet) from Spec’s accurate measurements. This level of inaccuracy can significantly impact a property's energy rating, and the implications are profound. In 56% of cases, EPCs understated the property size, while in 44% of cases, they overstated it. This inconsistency in measurement not only skews the energy performance data but also affects the legal standing of properties on the rental market.

The root of this problem lies in the widespread use of the Reduced Data Standard Assessment Procedure, employed in 90% of lodged EPCs. This method relies on standardized values rather than actual measurements of key features. Limited measurement practices, combined with the use of average storey heights, lead to wide margins of error. The primary dwelling volume input factor, crucial for accurate energy assessment, often suffers from these generalized assumptions.

The report advocates for modern measurement tools and accurate volumetric assessments to improve EPC accuracy. By precisely considering the actual space to be heated versus heat loss areas, the reliability of EPC assessments could be dramatically enhanced. This recommendation is not just a call for better technology but a necessary step towards ensuring compliance and mitigating risk for landlords.

The Energy Performance of Buildings Act 2012 mandates that all properties marketed for sale or let in England and Wales must have an EPC. These certificates, produced by accredited Domestic Energy Assessors (DEAs), provide a snapshot of a property's energy performance and environmental impact. However, the current inaccuracies undermine this system, putting landlords at risk of non-compliance and potential legal actions.

In light of these findings, the white paper recommends a series of actions for the domestic energy assessment market. It highlights the need for improved measurement standards and more accurate assessments to protect landlords, certification bodies, and ultimately, the environment. The implications of inaccurate EPC ratings are far-reaching, affecting not only regulatory compliance but also the broader goals of energy efficiency and sustainability.

Landlords must heed this warning: ensuring the accuracy of EPC ratings is not just a regulatory requirement but a safeguard against significant financial and legal risks. With over 17 million EPCs lodged to date, the call for reform is urgent. Accurate energy performance assessments are essential for a sustainable future, and landlords play a crucial role in this endeavour.