Blog > Category > Posted: 2022-Jun-28, Updated: 2023-Mar-14

The battle of the panes - single-glazing vs multi-glazing

double-glaze vs multi-glaze
If you are going through the process of having your windows replaced, you'll may hear conflicting arguments for or against double-glazed vs multi-glazed windows.

Are you on the hunt for high-quality and energy-efficient windows that also offer the best value for your money? Look no further! To make the most informed decision, it's crucial to do your own research and draw your own conclusions. Our blog post offers an unbiased overview of the various factors affecting window prices and performance, providing you with the necessary information to choose the best options for your home and family. Don't settle for subpar windows when you can have the best.

Glass Efficiency

Before you start, here are a number of glass attributes that affect a window’s efficiency.

  1. The number of (glaze) panes of glass
  2. The thickness of the glass
  3. Coatings on the glass
  4. Space between the glass
  5. The Material separating the glass (spacers)
  6. The gas between the glass
  7. The frame holding the glass in place

Lots to consider. Unfortunately, these attributes are rarely published and available to the average consumer. That’s why Energy Ratings are so important, they are the only standardized unbiased measurements (tested and measured by a neutral authority) available to help you make an honest comparison between windows.

Measuring Energy-Efficiency

The best resource for honest energy-efficiency measurements is available from the NRC Canadian Government-sponsored Energy Star website, here you can search for windows by a variety of queries.

Below are the main energy-efficiency ratings as they pertain to glass. Keep in mind that window manufacturers typically provide customers with several glass options to help produce the desired result (e.g. less light, less heat, more insulation…) which can lower or raise energy-rating values.

Energy Star Specs - double/triple glazing
  1. U-factor (UF) - heat loss through frames, spacer and glass
  2. Solar heat gain coefficient (SHGC) - heat transmitted and absorbed that is subsequently released inward
  3. Visible transmittance (VT) - is the amount of light in the visible portion of the spectrum that passes through a glazing material

Energy efficiency is great, but what about home comfort?

In Ottawa (climate zone 3) the energy-efficiency prime directive is focused on keeping heating costs down in the winter as statistics show heating costs far outweigh cooling costs. However, in many cases, energy efficiency may mean a sacrifice in home comfort.

Unfortunately, some of the things that make a window more efficient can also result in less desirable effects:

  • Excessive heat in a room in the summer
  • Excessive brightness in a south-facing window all year round
  • Furniture damage due to UV rays

This is exactly why most window manufacturers give you varying levels of glass options and why when you are buying windows, even though there are manufacturing standards, you cannot really make apples-to-apples comparisons.

Comparing double-glazed windows to triple-glazed windows

Trying to decide between triple and double glazing? Let's break it down. First, let's assume that both options use the same type of glass, gas, and spacer. So what's the difference? Triple glazing has one extra pane of glass, which means it offers slightly better insulation and soundproofing than double glazing. However, triple glazing is also more expensive than double glazing, so you'll need to weigh the benefits against the cost.

Additionally, triple glazing is thicker and heavier than double glazing, which can make it more difficult to install and potentially limit your design options. Ultimately, the decision between triple and double glazing will depend on your specific needs, budget, and preferences.

Home comfort

  • Triple-glazed windows are typically better than double-glazed windows at helping to keep the air temperature inside the home at consistent temperatures.
  • Triple-glazed windows typically allow for higher levels of humidity and lower condensation than double-glazed windows.

Performance and weight

Double-glazed windows

  • Weigh less than triple-glazed windows.
  • Do not have to be as strong as triple-glazed windows to support the glass.
  • Are easier to lift for installation.

Triple-glazed windows

  • Weigh more than double-glazed windows.
  • Quality triple-glazed windows are engineered to handle additional glass weight and are unaffected by the weight when operating.
  • If concerned about weight and durability, look for products with higher-year warranty coverage.

Free heat and light

  • Double-glazed windows allow a little more light and solar heat into the home than triple-glazed windows.
  • Standard triple-glazed windows are slightly better at filtering out UV rays than double-glazed windows.

Thermal insulation

Window glazing and thermal insulation are closely related. The glazing, or the number of panes of glass in a window, is one of the factors that determine the thermal insulation properties of a window. Double or triple glazing, for example, creates insulating air pockets between the panes of glass, which helps to reduce the amount of heat lost through the window. Low-emissivity (Low-E) coatings, which are often applied to one or more of the panes of glass in a double or triple-glazed window, can further improve the window's thermal insulation by reflecting radiant heat back into the room. The higher the number of panes in a window, and the better the insulation properties of the glass, the more energy-efficient the window will be, which can lead to lower energy bills and a more comfortable home.


Low-emissivity (low-E) glass is a type of glazing that has a microscopically thin coating of metal oxide on the surface of the glass. This coating helps to reduce the amount of heat that is transferred through the glass, making it more energy-efficient. Low-E glass can be used in single, double, or triple-glazed windows to enhance their thermal performance. It is a popular choice for energy-efficient windows because it can reduce heat loss in the winter and heat gain in the summer, leading to lower energy bills and increased comfort.


Window glazing can have a significant impact on the cost of a residential window. The more glazing layers a window has, the more expensive it tends to be. For example, single-pane windows are typically the least expensive, while double-pane and triple-pane windows are more costly due to the added materials and manufacturing process required. Additionally, windows with special glazing options, such as low-emissivity (Low-E) coatings or gas fills, can also increase the cost. However, it's important to keep in mind that while the upfront cost of a more energy-efficient window may be higher, it can result in long-term cost savings by reducing energy bills.


Window glazing can affect window condensation. Triple-glazing windows are generally the best option for preventing condensation as they have a lower U-value and better insulation properties, reducing the temperature differential between the inside and outside of the glass. This, in turn, reduces the likelihood of condensation forming on the window surface. Additionally, some triple-glazing windows have an argon or krypton gas fill between the panes, which also helps to reduce condensation. Overall, the type of glazing used, as well as other factors such as ventilation and humidity levels in the home, can all affect the likelihood of window condensation.


Window glazing can affect the amount of sound that enters a home. Generally, windows with triple-pane glazing provide better sound insulation than windows with single-pane glazing. The additional layers of glass and air pockets in triple-pane windows can help to absorb soundwaves and reduce noise transmission. Additionally, there are specialized acoustic glazing options available for even greater sound insulation.

Related topics

What is Low-E Glass?

What are Energy Star energy ratings?

Keeping your energy costs down and comfort level up

Infographic - What’s to know about window glass

Infographic - The Protective Properties of Window Glass

Window glass is more than just plain old glass

Need more information?

Are you looking to increase the energy efficiency of your home? Learn about the pros and cons of single vs multi-glazing and how they can impact your energy bills. Contact us to speak with one of our experts and find the best solution for your home.

Request information | 613-838-2211 | Request a quote