Modern architecture often favours light-filled spaces, with large glass facades and skylights becoming increasingly popular in UK homes. While these features look stunning and create airy interiors, they can also have a significant effect on a property’s Energy Performance Certificate (EPC) rating.
Why EPC Ratings Matter
An EPC measures a property’s energy efficiency from A (most efficient) to G (least efficient). Homes with large glass areas are assessed carefully because glazing plays a crucial role in heat retention and energy use. Learn more about the EPC process on our Services – EPC Assessors in London page.
How Large Glass Areas Affect EPC Ratings
Heat Loss in Winter
Glass has lower insulating properties than solid walls. Homes with extensive glazing may lose heat more quickly, lowering efficiency and EPC scores.Solar Gain in Summer
While skylights and glass facades can provide free warmth in cooler months, they may cause overheating in summer. This could increase cooling demand, impacting energy efficiency.Window Glazing Type
Single Glazing → Poor insulation, significantly reducing EPC performance.
Double Glazing → Good insulation and a cost-effective upgrade.
Triple Glazing → Best thermal performance, helping offset large glass surfaces.
Orientation of Glass
South-facing facades may benefit from solar gain, while north-facing glazing often leads to higher heat loss.Ventilation and Shading
Skylights and large windows can be fitted with blinds, shades, or smart glass to balance natural light and energy control.
Improving EPC Ratings in Glass-Rich Homes
Upgrade Glazing: Opt for high-performance double or triple glazing.
Use Low-E Coatings: These coatings reflect heat back inside during winter.
Install Thermal Curtains or Blinds: Reduce heat loss at night and control overheating during the day.
Add Roof and Wall Insulation: Compensate for weaker glass insulation with stronger building fabric.
Smart Heating Controls: Optimise energy use in homes with fluctuating heat gain.
Do You Need a New EPC After Installing Skylights or Glass Extensions?
Yes. Any major structural change, like adding skylights or a glass façade, requires a new EPC if you plan to sell or rent. You can check our Pricing page for costs, or quickly arrange an assessment via our Booking page.
Expert EPC Advice for Modern Homes
Balancing aesthetics with energy efficiency is essential when designing homes with extensive glazing. Our accredited assessors can provide tailored guidance to ensure your property meets EPC requirements. Learn more about us on our About Us page, or Contact Us for expert advice.
