Double glazed windows refer to two layers of glass with a layer of inert gas in between them and separated by a spacer.

Once sealed, the glass panes become airtight. Plus, the insulation is twice as much as compared to single glazed units. The glass is then fitted into window frames, adjusting its width to accommodate the two panes.


Double glazed units come with a spacer – a metal or polymer strip that acts as a separating agent between the two glass panes. Spacers usually contain a desiccant (drying agent) to eliminate moisture trapped in the air space.

What To Look For

The typical amount of space between panes is between 6mm to 20mm. For effective thermal performance, consider a minimum space of 12mm. For optimum air gap, a space of 150mm or higher is recommended especially if you want better acoustic control or to avoid disturbance from traffic and aircraft. However, the larger the gap, the lesser it can insulate your inner spaces effectively so you have to weigh your options based on your specific needs and expectations.

Advantages of Double Glazing

1. Lower Energy Consumption

overview-of-double-glazing-windows-2Losing heat through your traditionally built windows means wasted money on energy bills and fewer savings. Keep your house warm, comfortable and energy efficient not by just covering them with curtains but by installing double glazed windows. An average, semi-detached house with double glazed windows can save up to 20% on its energy consumption, based on the findings of the US Energy Department.

2. Improved Thermal Resistance

Double glazed windows are a wise investment and an ideal option for increasing your home’s energy efficiency while minimizing noise. And because the air gap between the two glass panes is tightly sealed, it provides more insulation. This added thermal resistance ensures there is less heat escaping during winter season and more cool air retained inside the house during summertime. In both situations, you will find yourself becoming less dependent on artificial heaters and air conditioning systems, thus, ultimately lowering your energy costs.

3. Maintaining Room Temperature

If you lean closer towards the window, the temperature of the glass panes has a direct impact on your comfort. Double glazing prevents outside temperature to affect the temperature of your interior spaces plus it minimizes condensation that is usually the culprit of molds and mildew formation.

4. Noise Reduction

overview-of-double-glazing-windows-4The effectiveness of double glazed windows goes beyond energy savings and better insulation. It is effective at minimizing medium to high frequency noise such as vehicles passing by, animal activities, and even conversations. The glass thickness between the inner and outer spaces also has a direct impact on further reducing unwanted sounds.

5. Added Security Protection

Double glazed windows provide better protection against unwanted intruders because two sheets of glass are more difficult to break than just a single one.

6. Glass Type

Double glazed windows come in different glass types, such as laminated and low-E, both of which have different level of capacity when it comes to noise control and energy efficiency. While low-E glass is best for prevention of heat loss, the thicker laminated glass panes on the other hand acts as a barrier from external sound waves to improve acoustic performance.


1. Non-Reparable

overview-of-double-glazing-windows-3Air trapped in the space between the two glass panes allows for better insulation. However, if there is improper installation and it is not an airtight seal, condensation will occur. Panes usually cannot be pulled apart or repaired. The entire window system has to be replaced to prevent further problems.

2. Trapped Heat

Trapped heat is welcomed and much needed during the winter months but it is the complete opposite during hot and humid days. Many homeowners usually install window tints to block the heat and prevent discomfort inside the house but it will cost you extra to do this.

If you are considering installing double glazed windows, find a reputable contractor around your area and request for a quote that will fit your budget.