More than 60% of landlords are unaware that having a valid EPC is a legal requirement, according to new research highlighted by Glevum Windows.

The figures come as an estimated 33.8% of privately rented homes in England currently fail to meet the proposed EPC C standard due to come into force by 2030. Glevum Windows warned that around two million landlords could ultimately face fines of up to £30,000 if properties are not upgraded in time.

Research from The Mortgage Works found that 62% of landlords did not know an EPC was legally required, while only 33% correctly identified the 2030 EPC C deadline. Meanwhile, 63% said they were unsure how much upgrades would cost.

The company said windows remain one of the most overlooked factors affecting EPC ratings, accounting for up to 25% of heat loss in a typical UK home. Around 10% of privately rented properties are also affected by damp, often linked to failed glazing, condensation and poor thermal performance.

The issue has become increasingly significant following the introduction of the Renters’ Rights Act and the extension of Awaab’s Law into the private rented sector, placing greater legal obligations on landlords to address damp, mould and excess cold.

Mike Donaldson, Managing Director at Glevum Windows, said: “The 2030 deadline feels distant, but the installation pipeline won’t wait, and landlords are only just waking up to the fact that windows are often the first thing an EPC assessor looks at.”

The figures highlight the growing compliance challenge facing landlords as energy efficiency standards tighten and pressure increases to improve housing quality across the private rented sector.