Cavity wall insulation has long been promoted as an effective way to improve a property’s energy efficiency. However, many homes with insulation installed in the 1980s and 1990s are now seeing these past upgrades backfire on their Energy Performance Certificates (EPC). If your EPC rating is lower than expected, outdated or degraded cavity wall insulation could be the hidden culprit.
How Old Cavity Wall Insulation Can Lower Your EPC Rating
While insulation is supposed to reduce heat loss, older cavity wall systems can degrade over time. Common problems include:
Moisture Ingress: Water penetration leads to damp insulation, which becomes thermally ineffective.
Slumping or Settling: Over decades, insulation material may sink inside the cavity, leaving gaps.
Incorrect Installations: Past methods didn’t always meet today’s installation standards, leading to poor coverage.
When an EPC assessor identifies these issues, the software will default to a “no insulation” or “partial insulation” scenario, drastically reducing the wall’s assumed thermal efficiency.
Can Degraded Insulation Really Cause EPC Failure?
Yes. In properties that rely heavily on cavity wall insulation for thermal efficiency (like mid-20th-century brick houses), failing insulation can drop your EPC score by one or even two bands. For landlords, this could mean falling below the Minimum Energy Efficiency Standards (MEES), making the property legally unlettable without remedial works.
What Are Your Options to Rectify the Issue?
Professional Cavity Wall Inspection: Arrange for a thermal imaging survey or borescope inspection to assess the insulation’s condition.
Extraction and Refill: If the insulation has failed, a professional extraction and reinstallation of modern insulation material is essential.
EPC Reassessment Post-Upgrade: Once remedial works are complete, you’ll need a fresh EPC assessment to reflect the improvement.
At Urgent EPC, we offer same-day EPC reassessments after insulation upgrades. Our qualified assessors ensure that improvements are correctly recorded, giving you the best possible rating.
Don’t Let Hidden Defects Damage Your EPC Score
Old cavity wall insulation is a classic example of a once-beneficial upgrade that can now work against you. If your EPC score doesn’t reflect the expected energy efficiency of your home, a detailed property assessment is crucial. Reach out to Urgent EPC for expert advice and fast-track EPC assessments at competitive pricing plans.
At Urgent EPC, we offer professional guidance on how to boost your EPC rating, including heating system evaluations. If you’re planning to install a heat pump or want to reassess your current EPC, we can help you get fast, certified results.
Call Us Today: +447741 812864
Email: info@urgentepc.co.uk
