When assessing whether a residential building will overheat, CIBSE Guide TM59 should be used. This is not only considered a robust design methodology step, but is a requirement for London Plan and the new Part L 2021.
Since the introduction of the Minimum Energy Efficiency Standards (MEES) in England to an EPC ‘E’ for leases and the expected strengthening of this to EPC ‘B’ by 2030, the Scottish EPC methodology has come under some scrutiny.