Windows
In temperate and cooler climates, northerly glazing should have a higher SHGC to allow for more solar heat gain. In hot climates, glazing should have a low SHGC to reduce solar heat gain. “Insulation in your windows is important all year round, regardless of orientation,” Armstrong says. “However, it’s the west you need to be concerned about in summer.” West- and east-facing windows with a low SHGC will reduce overheating in summer. Armstrong recommends double glazing or low-E coatings for optimum performance in all seasons, so as not to miss out on passive heat gain in winter.
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? Climate and reliance on heating and cooling will influence which glazing will work best and where. For example, insulation is important in colder climates such as Victoria, whereas sun protection is a priority in hotter environments such as Queensland. 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.
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. In colder climates where sun control is not a priority, adding a low-E coating to the internal pane of glass can help keep a house warmer in winter.
Low-E glass: 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. “In the past you would need to use dark tints and thick glass to achieve performance, but with today’s coating technology, clear-coated glass such as low-E provides the same solar protection as tinted glass,” says Stegbar glass expert Carley Armstrong.
Double and 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. Windows such as Viridian’s LightBridge range can be tailored to address a variety of specific design needs, including noise reduction, privacy, security and UV-control. Stegbar’s thicker float glass, laminated glass, insulated glass units and secondary window units also significantly reduce noise levels.
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. “Glass now has a major influence on home design. Advancements in glass technology mean Australians can choose from a selection of glass options that offer different performance features,” says Samantha Anderson, business development manager at Viridian. “Smart homeowners looking to future-proof their home will look to performance glass products to create a home that feels good, functions efficiently and offers truly personalised comfort.”
When building with the environment in mind or looking to increase the energy efficiency of your home, upgrading to insulated glass makes a huge difference. Selecting double- or triple-glazed windows and/or thermal-break window and door frames lets you have large-scale glass openings that capture views and light without compromising on a comfortable indoor temperature.
Motorised window treatments Motorised blinds and curtains are the ultimate in convenience, allowing you to open and close your window treatments via remote control, smart phone or tablet. Companies such as Somfy Australia even allow you to open them via voice command with your Alexa smart-home device. Alternatively, have them linked to a sensor system so they open or close automatically according to the weather.
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