AS MANY as 2.5 million Energy Performance Certificates in the UK are wrong due to inaccurate measurement standards and practices and it means landlords could be unwittingly breaking the law.

One in four EPCs record the size of a property so inaccurately that it varies by more than 10 per cent from the actual measurement, according to a new report by property technology firm Spec.

It believes that this means that landlords are letting properties illegally as an estimated 35,000 E-rated properties are below the legal standard.

The report explains that outdated techniques to measure floor space can have a significant impact on the accuracy of EPCs and the problem is so acute and so widespread, that it means that tens of thousands of landlords may be unwittingly breaking the law.

Spec’s research highlights the limitations of most Domestic Energy Assessors’ (DEA) old-fashioned property measurement techniques, with the average discrepancy in property area coming in at 8.6 per cent or 87 square feet.

The firm says that floor space is a key component of the calculation carried out by DEAs to give a property its energy rating.

Accurate floor space measurements are essential for producing an accurate final EPC rating because as little as a one per cent change in property area can alter the overall EPC rating.

This is particularly important for residential landlords who must ensure that their property achieves an A to E rating to be legally let, or they can be fined thousands of pounds.