What Is Insulated Glass?

Insulated glass, also known as an insulated glass unit (IGU), is designed to enhance the thermal efficiency of windows and doors. These units consist of two or more panes of glass separated by a sealed air or gas-filled space. This setup significantly reduces heat transfer, making them far more energy-efficient than traditional single-pane glass. Insulated glass, commonly found in double-pane windows, is designed to enhance the thermal efficiency of windows and doors 

At Daylight Glazing, we supply and Fit high-performance insulated glass units that not only help regulate your indoor climate but also contribute to long-term energy savings and comfort. 

How Do Insulated Glass Units Work?

Insulated glass units eliminate the direct thermal bridge between the interior and exterior of your home. A single pane of glass acts as a perfect conductor of heat, allowing indoor warmth to escape in winter or letting outdoor heat in during summer. IGUs solve this by placing an air or gas-filled gap between multiple glass panes, effectively blocking heat transfer. 

The most commonly used gases in IGUs are argon and krypton, which are denser than air and less likely to transfer heat. This significantly enhances insulation and overall energy performance. 

Insulated Glass

Types of Insulated Glass Units

Daylight Glazing offers a range of IGUs to meet your needs: 

Double-Pane IGUs

Feature two panes of glass with an insulating gas or air in between. This is the most common and cost-effective insulated glass option. Insulated glass, commonly found in double pane windows, is designed to enhance the thermal efficiency of windows and doors 

Triple-Pane IGUs

Include three panes of glass with two insulating gaps. These offer superior insulation and are ideal for extreme climates or high-efficiency homes.

Argon Gas-Filled Units

Affordable and energy-efficient, argon is the most popular insulating gas used in IGUs. Insulated glass units, especially windows with argon gas, are a smart solution for homeowners looking to cut down on energy costs while maintaining indoor comfort.

Krypton Gas-Filled Units

A denser and more efficient insulating option than argon, ideal for smaller gaps in triple-pane glass. While more expensive, it delivers exceptional thermal performance.
Our IGUs can be used in windows, bi-fold doors, French doors, patio sliding doors, and other exterior glazed openings. Most of our insulated glass solutions also feature tempered safety glass for added protection and easier shipping.

Insulated Glass

One important factor that affects the performance of insulated glass units is insulated glass thickness. This refers to the total thickness of the unit, including both glass panes and the air or gas space between them. 

Standard insulated glass thickness for double-pane windows ranges from 20mm to 28mm, while triple-pane units can go up to 44mm or more. The optimal thickness depends on factors such as climate, noise control needs, and energy efficiency goals. 

Thicker insulated glass provides better thermal and acoustic insulation, especially when combined with gases like argon or krypton. 

Advantages of Insulated Glass Units

Enhanced Energy Efficiency

IGUs reduce the need for heating and cooling by limiting heat exchange through windows. This leads to lower energy bills and a reduced carbon footprint.

Improved Indoor Comfort

Insulated windows feel less drafty and help maintain a consistent temperature throughout your home. Say goodbye to chilly winter mornings and overheated summer afternoons.

Increased Property Value

Upgrading to double pane windows - or triple-pane insulated glass units can yield up to an 80–85% return on investment by boosting energy performance and curb appeal.

Versatile Application

Our insulated glass units are suitable for a wide range of residential and commercial installations—from casement windows to sliding patio doors.

Disadvantages of Insulated Glass Units

Higher Initial Cost

IGUs are more expensive upfront than single-pane glass, but the long-term energy savings usually offset the investment over time.

Difficult Repairs

Once an IGU is cracked or the seal fails, the insulating gas escapes. These units cannot be refilled, so replacement is the only effective solution.

Understanding Solar Heat Gain Coefficient (SHGC)

The Solar Heat Gain Coefficient measures how much solar radiation passes through a window. A lower SHGC means the glass allows less solar heat to enter, which is ideal for warmer climates. In contrast, a higher SHGC is beneficial in colder regions, helping to passively warm interior spaces. 

At Daylight Glazing, we tailor our glass solutions to meet your regional climate needs, balancing SHGC and insulation for year-round comfort. 

Upgrade with Daylight Glazing – The Experts in Energy-Efficient Glazing

With so many insulated glass uses, these units have become a standard choice for modern homes and energy-conscious building designs. Whether you’re building new or upgrading old windows and doors, Daylight Glazing offers premium insulated glass solutions tailored to your needs. Our products are engineered for performance, safety, and comfort—helping you achieve energy savings and a greener home. 

Need Help?

FAQs

Use weatherstripping, thermal curtains, window insulation film, or apply caulking around window frames to reduce heat loss. 

Install insulated curtains or thermal blinds, use draft stoppers along tracks, apply weatherstripping, or add a secondary glazing panel. 

Glass insulators can be found at local hardware stores, glazing suppliers, energy-efficiency retailers, or online marketplaces like Amazon or Screwfix or Daylight Glazing