Modern homes often feature large glass facades, floor-to-ceiling windows, and expansive glazed areas to maximize natural light and aesthetic appeal. While visually stunning, these design choices can significantly influence a property’s Energy Performance Certificate (EPC) rating.

1. Heat Loss and Thermal Efficiency

Glass has a higher thermal conductivity than most wall materials, meaning that homes with large glass facades can lose heat more quickly during colder months. This increased heat loss can lower your EPC rating unless energy-efficient glazing, such as double or triple glazing, is installed. Learn more about EPC assessments on our Booking page.

2. Solar Gain and Overheating

Large glazed areas can lead to excessive solar gain in summer, causing overheating and increased cooling energy demand. EPC software models typically account for seasonal energy use, so homes with poorly managed solar gain may see a reduction in their rating. Optimizing shading, blinds, or low-emissivity coatings can help mitigate this.

3. Insulation Considerations

The type of glass and framing materials used in large facades directly affects thermal performance. High-performance glazing with low U-values can improve EPC ratings, while standard glass may negatively impact the overall energy efficiency of the home. Explore our Residential EPC services for guidance on energy-efficient upgrades.

4. Impact on Heating and Cooling Systems

Homes with extensive glass areas may require more sophisticated heating and cooling solutions to maintain comfort while minimizing energy consumption. Properly designed HVAC zoning and smart thermostats can help balance energy use, positively affecting EPC scores. For personalized advice, contact our EPC experts.

Practical Tips for Homeowners

  • Upgrade to energy-efficient glazing: Double or triple glazing with low-emissivity coatings improves thermal performance.

  • Use shading solutions: Blinds, overhangs, or smart shading systems reduce unwanted solar gain.

  • Optimize HVAC zoning: Ensure heating and cooling systems efficiently manage energy use across large glazed areas.

  • Accurate EPC assessment: Make sure all glazing and energy-saving measures are included in your EPC assessment.

For more information about how modern design choices impact EPC ratings, visit our About Us page.