Insulate. Insulate. Insulate.
Insulating ﬂoors, walls and ceilings is one of the best ways to ensure an energy-efﬁcient house and mitigate heat gain and loss. However, it’s important to combine insulation with passive design techniques. For example, in warm or mixed climates if your home is not properly shaded or doesn’t allow for cross-ventilation, heat can build up and become trapped by the insulation, creating an ‘oven’ effect. When looking at insulation, it’s not the thickness of the insulation product that counts, but the R-value, and the higher the R-value, the better the thermal performance. Architect and builder Oliver Steele from Steele Associates advises homeowners, where possible, not to scrimp on insulation. ‘[It’s] not expensive to install when building, and is very expensive to retroﬁt...[but] nothing else gives you as good a value for money in terms of comfort and energy cost savings.’ (Read more about Oliver on p.34.)
WHAT IS GREENSMART?
IA GreenSmart is a way of building which is respectful of the environment and its inhabitants. A registered brand of the Housing Industry Association (HIA), GreenSmart was developed in 1999 to provide a means for anyone involved in building or renovating a home to learn about the principles of sustainable design. GreenSmart accredited homes represent leading practice in environmentally sustainable housing design. These homes: • demonstrate improved energy, resource and water efﬁciency • enable homeowners to waste less and recycle more • reduce waste from the building process • are healthier for occupants • are built using improved site management methods. Efﬁcient hot water systems; sustainable timbers; masonry products with high thermal mass; effective insulation; lower toxicity paints; water-saving and greywater systems; energy-efﬁcient lighting, heating and cooling – all of these things contribute to sustainable living. The long-term beneﬁts of designing and building or renovating a home to include GreenSmart principles can include lower energy and water bills, a warmer house in winter, a cooler house in summer, increased resource efﬁciency, a healthier home for the occupants, and less waste going to landﬁll. Building homes that include environmental features doesn’t have to cost the earth. It’s more about how you build (or renovate) rather than what you build. With just a few simple choices you can achieve environmental living at a price that suits you. The design and choice of materials make all the difference. The key principles of building this way include correct orientation on site to maximise solar design principles, natural ventilation, insulation (the ﬁrst line of defence against the external elements after passive solar design), thermal mass (the ability of a material to absorb heat energy), and ﬂooring. Building the HIA GreenSmart way can help you achieve comfortable and healthy living while saving energy, water, money and the environment.
Select window glazing to suit the climate you live in.
When selecting windows during a new build or renovation, where you live will help determine what type of glass will best provide greater comfort and energy efﬁciency. Solar heat gain coefﬁcient (SHGC), which is expressed between 0 and 1, measures direct heat from sunlight through a window. In cooler climates, you should opt for high SHGC, while in temperate climates a mid-range SHGC or a mix depending on which direction the window faces is preferable. In hot climates you should use low SHGC throughout your home. U-value refers to how well a window is insulated; the lower the better. Low-E glass and Insulating Glass Units (IGUs), commonly referred to as double glazing, greatly improve the insulation performance and energy efﬁciency of a window compared to standard glass. When retroﬁtting, however, window ﬁlms can be a costeffective way to reduce solar heat gain through existing windows in warmer climates (though this may impact light ﬁltration).
Photo courtesy Justin O’Connor Builders