Sustainable design tips to ensure your new home is energy efficient - Tasmanian Edition

Get that Hobart summer feeling year round with these tips

This is one of a series of articles that will detail some of the most cost-effective ways to ensure your home stays comfortable year-round. Making the right choices during the design phase is the best way to achieve the goal of a thermally efficient building.

Australia has a wide variety of climatic conditions which generally require a different design response for the best thermal performance. This article will focus on measures to improve the thermal performance of your house in Tasmania.

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1. Orientation – Try to keep living spaces to the Northern side. Most lots in Hobart and Southern Tasmania will have great views to the South, in these cases try to at least get some windows facing North, highlight glazing can work well here. Try to align the house so that the longest wall is facing North, this will gather the most sunlight to help warm your home.

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2. Windows – The best performing houses in Tasmania have most of the glazing facing North, little to none facing South and minimal glazing to the East and West. If you have a nice view to the South, consider picture windows to frame the view, rather than full height glazing. Even shortening full height windows by bringing them up off the floor will improve thermal performance. The additional cost of double glazing in conditioned spaces will soon be repaid in energy savings and the luxury of sitting by the window in winter without feeling cold.

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3. Lighting – Choose a style of downlight that is approved to have insulation installed directly above it. This will avoid having costly gaps in insulation which allow warm air to escape.

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4. Choose dark colours – Having a dark-coloured roof and walls will absorb radiation from the sun that would otherwise end up being reflected back into space. Light feature colours can be used on garages or on shaded walls such as those under a front porch.

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5. Insulation – Generally the more insulation you can fit into the home the better.

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Walls can vary depending upon construction style but broadly speaking should have an air gap formed by reflective vapour permeable wall wrap or a highly vapor permeable, non reflective wrap to minimise condensation risk. Wall batts should be the highest R Value you can fit – Usually up to R2.5 batts will make sense economically.

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The roof can also vary, but usually the most cost effective or bang for buck solution is to combine ceiling batts of R4.0 or higher with a reflective insulation blanket under the roof sheeting.

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A timber floor should have batts a minimum of R2.5, there are some reflective foam products that can be effective here also. A concrete slab will benefit from a polystyrene board or similar placed underneath.