Windows appear to serve a simple function: they allow the occupants of a home to see outside, and let natural light and fresh air filter through. But there’s more to glazing than meets the eye; the windows you choose can have a significant impact on your home’s thermal performance and energy efficiency. According to the Australian Government up to 40 per cent of a home’s heating energy can be lost, and up to 87 per cent of its heat gained, through windows. So choosing the right windows can not only make your home more comfortable naturally, but can make a big difference to your energy bills too.
Why It Matters
Glass windows and doors can impact the thermal performance of a building, contributing to the energy efficiency and comfort of a home. Windows lose more heat in winter and gain more heat in summer than any other surface in the home. In many parts of Australia, the priority is to reduce solar heat in summer in order to keep the house cooler, and maximise solar heat in the winter so it stays warmer. Quality glazing can help do this by improving the efficiency of glass windows and doors. Good glazing reduces heat gain and loss, thereby helping to minimise the use of artificial heating and cooling in a building.
Types Of Glazing
Energy-efficient windows come in a variety of forms, including double- and triple-glazed and those made with low-E glass. Various coatings can also improve their performance.
Double & Triple Glazing
Double- and triple-glazed windows have at least two sheets of glass with an inert gas such as argon (typically cheaper) or krypton between them. The gas, which is a poor thermal conductor, slows the passage of heat through the glass. The entire unit is sealed in the frame for lower heat exchange rates. These types of windows can also feature soundproofing qualities to reduce the impact of outside noise, as well as UV protection to prevent harmful rays from fading your furniture and finishes. Double-glazed windows can reduce heat loss or heat gain by almost 30 per cent in comparison with single-pane aluminium windows. Triple glazing performs even better and is ideal for colder environments and extreme northern climates. The extra pane of glass, however, does make them thicker, heavier and more expensive.
Low-E (low emissivity) glass has a transparent coating – an invisible layer of metallic oxide – that minimises the amount of heat that passes through the glass while still allowing light to flow through. Low-E coatings add to the cost of a window, but they can cut your energy costs. Low-E glass reduces solar gain in winter and summer. Therefore, homeowners in colder regions may choose coatings that maximise solar heat gain, particularly in winter, while those in warmer climates may choose coatings that reduce solar heat gain in summer. Low-E coatings are often used to complement double glazing so as to provide even better thermal efficiency. They can be tailored to let the sun’s energy in or to block it out.
Optimise Your Glazing
High-performance glazing costs more than single-pane windows. So if you’re building or renovating on a budget, which rooms of the home and orientations are worth splashing out and where might you use a cheaper alternative? Energy-efficient glazing should ideally be used in every part of the house. But rather than taking a ‘one-type-fits-all’ approach, you can optimise thermal performance and keep the budget under control by choosing different glazing types based on room use, orientation and climate. Invest in the rooms that are used the most, such as living and family spaces, to increase the comfort level and reduce heating and cooling costs. For north-facing living spaces, which are exposed to direct sunlight, consider a glass that reduces UV exposure and glare. Bedrooms that are used less frequently during the day have less need for energy-efficient glazing.
At Hurst Homes Energy Efficiency is important to us as we know its important to you. With over 30 years building experience in Wagga, we know the climate and know how to orientate your home to maximize energy efficiency. Just another reason why we are considered Wagga’s Best Builder. For a no-obligation building consultation contact a friendly member of our team today!
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