Windows contribute significantly to the energy efficiency of your home, which is why double-glazing is a popular choice. While they are more costly than standard single-glazed windows, the advantages are making them an attractive option when you are building a new home or renovating your existing home. On hot days in Australia, the majority of the heat enters your home through the windows. In winter time, windows account for almost half the heat loss. In this article, we explain what double-glazed windows are, the difference between single and double-glazed, and the advantages of windows with double glazing for your home.
What are Double-Glazed Windows?
Double-glazed windows are windows with two panes of glass with a space between them. The open space is usually filled with a gas such as Argon or Krypton, and measures at least 12mm. The gap is sealed with a gas vacuum, and acts as a break between the two layers of glass, providing additional insulation and soundproofing. When double-glazed window panes are fitted into a framing material like uPVC, they offer a multitude of benefits contributing to the living comfort, energy efficiency, and value of your home.
Single-Glazed vs Double-Glazed Windows
As the name suggests, single-glazed windows are windows with one pane of glass, and double-glazed windows have two panes of glass separated by an air gap. With only one pane of glass and no insulation barrier, single-glazed windows tend to leak more heat in winter and gain heat in summer. Double-glazed windows, on the other hand, provide an extra layer of protection from the elements, and reduce the amount of solar energy passing through them. Comparatively, double-glazed windows have better insulation and durability, resulting in reduced electricity bills.
Single-glazed windows have a cheaper upfront cost compared to double-glazed windows. However, the long term effect is higher electricity bills, and potential repairs which may impact your ongoing finances over time.
Advantages of Double-Glazed Windows
With their two panes of glass and crucial vacuum gas sealed gap, double-glazed windows have a myriad of benefits from cutting energy costs to providing a more comfortable ambient temperature. We list the main advantages of double-glazed windows here.
- Energy efficient. Double-glazed windows are very energy efficient, as they reduce heat loss or heat gain by up to 30 percent, reducing heat loss in winter and reducing heat gain in summer.
To be energy efficient, simply means to use less energy to perform the same task, which double-glazing on windows does, eliminating energy waste with its two pane system.
To find out how energy efficient a window is, there is an energy rating system in Australia called WERS (Window Energy Rating Scheme) . This rating lets you know how a product performs in terms of energy efficiency. WERS rates the annual energy impact that a window has on an entire house and accounts for the energy contribution of both the glass and the frame. Windows are rated separately for both heating and cooling, so a window will have two ratings based on a ten-star scale.
- Lower power bills. Because of the insulation abilities, double-glazed windows result in lower power bills. Double glazing means there is less heat being lost when the heater is running, and less heat entering the home on hot summer days. By regulating the ambient temperature to comfortable levels, the air conditioner and heater use is reduced, so less power is used. With half of a home’s energy used by heating or cooling, this means massive savings on electricity bills.
- Noise reduction. There is a huge difference in noise reduction with double-glazed windows. If you live near a busy road, or have loud neighbours, the sound is drastically reduced and barely audible. Double glazing is not the same as soundproofing, but it can reduce noise by between 20 and 65 percent depending on the type and quality. That is equivalent to about 35dB which is a significant reduction. When combined with the noise-reduction qualities of uPVC window frames, the sound levels will be at the lower end of the spectrum.
The reason double glazing reduces the noise has to do with the second pane of glass and insulation. When noise hits a single glazed window, the pane vibrates, which causes the inside of the glass to vibrate and that is passed on as sound to the ears. The extra layer of glass with a double-glazed window reduces the amount of vibration inside the home, reducing the noise.
- Increased insulation. Double glazing works on the same principle as insulation, as a thermal resistant barrier which inhibits the migration of thermal energy in and out of the house. Instead of insulation in the walls, this insulation is in between two panes of glass with a gap that prevents heat transfer. This insulation reduces the amount of hot air between the inside and outside of the house. The result is the air inside stays cooler or warmer for longer than a single-glazed window.
- Increased security. Double-glazed windows are more secure than single glazed as they have two panes of glass that are harder to break. This means it will be safer for those with small children as the window is less likely to shatter. Additionally, the sheer strength of double-glazed windows may be a deterrent to potential burglars. If you combine double-glazed windows with the durable and stable characteristics of uPVC, accidental damage and potential home intrusions will be reduced even further.
- Boost property value. Having double-glazed windows already installed in a home increases the property value. Potential buyers will most likely be willing to pay more for a home knowing that the cost of double-glazed windows and installation is already taken care of, and that energy bills will be reduced. Additionally, the home will be more serene with the noise reduction qualities of the double-glazed windows.
- Prevent mould forming indoors. Double-glazed windows protect against mould growth because of their insulation properties. Mould needs a moist environment to grow but double-glazed windows prevent moisture build-up inside the home with their two layers of glass and insert layer wedged between them. The consistent surface temperature achieved with double-glazed windows reduces the likelihood of water vapour that causes mould spores to form.
- Reduces condensation. Condensation on the inside pane of windows occurs when warm, humid air comes into contact with cold glass. This is most common with single-glazed windows that don’t have the insulation to protect from the elements. Double-glazed windows, on the other hand, reduce the possibility of condensation because the double glass prevents the window from getting too cold. The two panes of glass and air gap in between helps to keep the internal pane of glass close to room temperature. To further reduce the possibility of condensation, combine double-glazed windows with uPVC frames for the ultimate thermal insulation.
- Suitable for hot and cold climates. Double-glazed windows are suitable for all weather conditions and climates. Whether in the middle of winter or the height of summer, double-glazed windows stop the heat transferring from one side to the other. This means, in winter, it stops the heat from escaping to the outside of the building. In hot weather, it limits the amount of heat energy from outdoors entering the home. The benefits of double-glazed windows can be felt all year round, regardless of the season.
- Reduces fading. Double-glazed windows combat UV rays that can ruin the interior of the home and your precious belongings. Fading and dicsolouration of carpets, furnishings and even photos is the result of UV rays entering the home. In fact, 45 percent of any fading is because of UV rays from the sun causing damage over a period of time. Single-glazed windows offer little protection from harmful UV rays. Double-glazed windows, on the other hand, with their two layers of glass and insulated middle layer, deflects the UV rays and reduces the likelihood of any fading.
Disadvantages of Double-Glazed Windows
The benefits of double-glazed windows far outweigh any disadvantages. However, it is important to have a balanced view when deciding which type of window is right for you. We list the disadvantages of double-glazed windows here.
- Initial cost is more. Double-glazed windows will cost more initially to buy and install. That is because there are two panes of glass as opposed to single-glazed with one window pane. They are typically thicker than single-glazed windows and may take longer to install. If double-glazed windows need to be replaced in the future, it is also worth considering the potentially higher replacement costs. According to hipages, double-glazed windows will generally cost 25 to 35 percent more than a standard, single-glazed window. When considering cost, remember the savings on energy bills in the long term.
- Cannot be repaired. When the glass in a double-glazed window is broken, it cannot be repaired. Both panes of glass need to be replaced to maintain the window’s efficiency. You also cannot replace the glass yourself as it requires special tools, knowledge and expertise. It is best to contact a windows professional to replace the glass safely.
- May not match homes with older architectural styles. Double-glazed windows tend to give a home a modern look. This is ideal for modern or contemporary designs but may clash with homes that have older architectural styles. There are some experts in double-glazed windows, however, that can offer windows in a large variety of styles and finishes to blend with your home’s character and style.
Double glazing on windows has so many advantages that it is becoming a popular choice for new homes or renovations. Double glazing ensures energy efficiency, reduces bills, and provides a quiet and peaceful environment with its significant noise-reducing features. Our guide explains everything you need to know about double-glazed windows, their advantages and disadvantages to help you decide what is right for you. For further information, contact the experts in all things windows at Windows for Life.
