Energy Performance Certificates have a range of flaws, with their inability to reflect real-world energy performance being the biggest challenge. Desk-based assessments with out-of-date software are doing nothing to improve the market value of decarbonised homes and do not accurately reflect the progress the country is making in improving the energy efficiency of housing stock. Given their role underpinning Government policy and targets, EPCs should nevertheless be retained but thoroughly overhauled to ensure that they represent an accurate assessment of the improved energy performance of buildings.