What is an IGU?

An Insulated Glass Unit (IGU) is a type of window made from two or more panes of glass separated by a spacer, creating a sealed air or gas-filled space between the panes. The spacer is usually made from metal or durable plastic and may be filled with inert gases like argon or krypton to enhance insulation. Depending on the number of panes, IGUs are often referred to as “double-pane” or “triple-pane” windows.

The main purpose of an IGU is to improve energy efficiency by reducing heat transfer between the interior and exterior of a building. This barrier helps keep your home or business warmer in the winter and cooler in the summer, while also reducing the workload on heating and cooling systems — which can lower energy costs over time. By maintaining a more stable indoor temperature, IGUs contribute to overall comfort and sustainability.

In addition to energy savings, IGUs provide a range of other benefits:

• Noise reduction: The sealed layers of glass help block exterior sounds, creating a quieter indoor environment.

• Enhanced durability: The multi-pane design is more resistant to impact and temperature-related stress than single-pane windows.

• Improved security: IGUs are harder to break through, adding a layer of protection for homes and businesses.

• Condensation control: Properly sealed IGUs reduce the chance of moisture forming between panes, helping prevent mold and water damage.

IGUs are widely used in both residential and commercial settings because they combine performance, efficiency, and aesthetics. From modern homes to office buildings, they allow natural light to fill spaces while keeping energy costs and environmental impact low.

At Two Panes Glazing, we specialize in IGU installations, replacements, and repairs, ensuring your windows deliver optimal energy efficiency, comfort, and long-term performance. Understanding how IGUs work and why they matter can help you make informed decisions when upgrading or maintaining your windows.