When you receive an Energy Performance Certificate (EPC), the document doesn’t just provide a rating—it also lists tailored recommendations to help improve the property’s energy efficiency. One of the most common suggestions is improving air tightness.
But what does this mean, why does it matter, and how do air tightness improvements affect your EPC rating?
At Urgent EPC, we provide fast, reliable Residential EPC assessments, along with practical advice to help property owners act on recommendations.
🏠 What Is Air Tightness?
Air tightness refers to how well a building prevents uncontrolled air leakage through gaps, cracks, and weak points in the structure. Poor air tightness allows heated or cooled air to escape, making your heating system work harder and increasing energy bills.
Typical leakage points include:
Window and door frames
Roof joints and loft hatches
Service penetrations (pipes, cables, ducts)
Floor and wall junctions
🔍 Why Do EPCs Highlight Air Tightness?
EPC assessors use SAP (Standard Assessment Procedure) or RdSAP software to model the energy performance of a property. Air tightness is a key factor because:
Heat Loss Reduction – A more airtight property loses less heat, reducing the need for constant heating.
Energy Efficiency – Improved airtightness means lower carbon emissions and energy consumption.
Better Comfort – Reduced drafts improve indoor comfort and stability of temperatures.
Higher EPC Rating – Even small improvements in airtightness can shift a property from a lower band (E/D) to a more desirable rating (C or above).
👉 Learn more about the EPC process on our About Us page.
✅ EPC Recommendations for Air Tightness Improvements
If your EPC highlights air tightness as an area for improvement, the recommendations may include:
Sealing gaps and cracks – Using mastic, foam, or tape around frames and junctions.
Upgrading windows/doors – Installing double or triple glazing with insulated frames.
Loft insulation sealing – Ensuring insulation and vapour barriers are continuous.
Improving service penetrations – Sealing around pipework, electrical fittings, and ducts.
Controlled ventilation – Pairing airtightness with MVHR (Mechanical Ventilation with Heat Recovery) systems to ensure good indoor air quality.
📊 Example Impact on EPC Ratings
A poorly insulated 1970s semi-detached home with gaps around windows and doors may score E on its EPC.
By sealing air leakage points and adding draught-proofing, the same property could improve to a D or C rating, depending on other upgrades.
👉 If you’re in a hurry, our Same-Day EPC service can highlight these opportunities quickly so you can act fast.
⚡ Cost vs. Benefit
Air tightness improvements are generally:
Low-cost compared to larger upgrades like solar panels or heat pumps.
Quick to implement, often done in a day.
High-return, as they reduce energy bills and improve comfort immediately.
👉 Check our Pricing Plan for assessment costs and compare with the savings airtightness improvements can deliver.
📞 Next Steps
If your EPC report highlights air leakage issues:
Book a detailed assessment with Urgent EPC.
Review which recommendations are low-cost quick wins vs. long-term investments.
Implement improvements before your next EPC to secure a higher rating.
🌍 Final Word
Air tightness is a critical part of your home’s energy performance. By following EPC recommendations for sealing gaps, upgrading windows, and ensuring continuous insulation, you can reduce energy bills, improve comfort, and potentially boost your EPC rating significantly.
Whether you’re a homeowner, landlord, or developer, Urgent EPC can help you identify and implement airtightness improvements to achieve better energy efficiency.
👉 Start today by booking your Residential EPC assessment or request a Same-Day EPC if you’re on a deadline.
