When aiming for a better Energy Performance Certificate (EPC) rating, homeowners often focus on insulation and heating systems. However, small air leakage points, especially around pipework penetrations, are silent EPC killers. Gaps around pipes, ducts, and service penetrations can undermine the overall energy efficiency of your property, leading to a lower EPC score.
How Pipework Air Leakage Affects EPC Ratings
EPC assessments consider the airtightness of a building envelope, as uncontrolled air leakage increases heating demand and reduces overall efficiency. Common leakage points around pipework include:
Holes through walls or floors for plumbing and cables.
Gaps where boiler flues exit external walls.
Service penetrations in loft spaces, especially in poorly sealed conversions.
Unsealed ventilation ducts and extract fans.
When assessors spot unsealed or poorly finished pipework penetrations, they must apply default infiltration penalties in the EPC software, which increases assumed heat loss and can cause a 0.5 to 1 band rating drop.
Why Pipework Leakage Is Often Overlooked
Hidden Behind Fixtures: Kitchen units, bathroom fixtures, and skirting boards often conceal these gaps.
DIY Renovations: Unsealed service holes are common in properties with amateur plumbing or electrical work.
Loft and Garage Spaces: Service penetrations into cold voids are rarely sealed adequately.
Builders Prioritising Access Over Airtightness: Pipes are often routed through oversized holes for ease of installation, leaving significant gaps unsealed.
Simple Solutions to Eliminate Pipework Air Leakage
Use Expanding Foam Sealants: Ideal for larger gaps around pipes.
Apply Airtightness Tapes and Gaskets: For flexible sealing around awkward penetrations.
Retrofit Pipe Collars: Particularly useful around boiler flues and ventilation ducts.
Inspect Hidden Areas: Under sinks, behind baths, and in lofts for unnoticed leakage paths.
At Urgent EPC, we regularly advise homeowners on simple airtightness improvements that can make a measurable difference in their EPC rating.
Book an EPC Assessment to Reflect Airtightness Improvements
After sealing up those hidden leakage paths, ensure your efforts are properly accounted for with a same-day EPC assessment from Urgent EPC. Our experienced assessors ensure no efficiency gains are overlooked. Check our pricing plans for affordable assessment options.
Expert EPC Advice for Air Leakage Issues
Unsure if hidden air leaks are hurting your EPC score? Contact Urgent EPC for tailored advice and practical solutions to boost your property’s airtightness performance.
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
