The recent Melbourne Home Show was an ideal opportunity to find out what builders and suppliers are offering in terms of sustainable design tips. Libby and I planned a mix of cruising the aisles to look at products and listening to expert speakers at the Sustainable Space (Living Green) stage. Here are the ideas and products that jumped out to us.
Ideas from speakers at the Home Show Living Green stage
Andy Marlow from Envirotecture spoke passionately about the process he uses to embed sustainable design principles in a new or renovated home. Here are a few of his design tips.
Design – list the specific requirements that you want to have for each room in the house. Getting the function right at the start is more important than beginning with a particular style of house in mind. To clarify our requirements, we’re going to put a load of cork tiles on one wall in our house and go mad with information pinned to the tiles. jThis room will then be an ideal location to hold design and review meetings as everything will be on display.
Zoning and ventilation – During winter, ensure that sections of the house can be closed off with doors to avoid heat loss to other rooms. However, locate the doors such that there is a ventilation path for breezes during summer when natural cooling can be used. Assume a breeze will travel in a straight line so, if possible, avoid putting obstacles in its way.
Thermal mass – water is a better thermal mass than bricks but tricky to include in a design. I wonder if there is an opportunity here to use some clever ideas in order to take advantage of this physical property (eg water storage that also doubles as thermal mass).
Shading – Don’t forget to provide external shading on walls as well as windows. Heating a wall in summer isn’t as bad as the heat input you will get from a window, but it’s still a heat source that could be reduced with appropriate shading.
Windows – Double glazing reduces the heat transfer through glass windows but there is more to do. In summer, the windows need to be shaded to reduce the amount of heat coming in. During winter, curtains and pelmets are used to further reduce the amount of heat leaking out through the glass. Pelmets are essential to prevent a convection current next to the window – warm air cooling as it contacts the top of the window, falling to the floor, drawing in more warm air, …
Later in the day, we heard Darren Evans (Solar Solutions Design) pass along his sustainable design tips. Here are some that caught our attention.
Local conditions – Find out as much as you can about the weather and immediate features which might affect the local conditions. How do trees affect the amount of sun? What is the prevailing wind direction? How would the land’s gradient affect water run off? The more you know about the conditions, the better decisions you can make during the design stage.
Thermal mass – A concrete slab is a good thermal mass for a house. Recommended not insulating the base of the slab. In winter, you want the warmth from the earth below coming through to keep the slab at a reasonable temperature. The opposite is true in summer when the earth temperature will be less than the air temperature so the slab can provide a cooling effect in the house.
Insulation – Don’t squash insulation batts into gaps as this reduces their effectiveness. Jamming a more expensive thick batt into a gap smaller than the batt’s design width is wasting money. Go for the batt that is designed for the available width.
Double glazing – Having a good seal around the windows is essential for reducing heat loss/gain. Otherwise, air leakage will reduce the effectiveness of the window package.
Roof space ventilation – Consider installing a thermostatically activated roof fan to vent warm air from the cavity between the roof and ceiling after a hot summer’s day.k
Interesting products on display at the Home Show
Zenit window systems – Impressive sealing system around the window and door frames which appeared to produce a tight seal when closed.
Trex decks – A decking material made from recycled plastic and reclaimed wood/sawdust. Apart from the attraction of using recycled materials, the product is low maintenance. There is no need to regularly paint/stain the decking to keep the colour and prevent weathering.
Energy management systems – We couldn’t find much about this subject. Most of what we saw were systems that switched heaters and coolers off at certain times. One supplier that possibly did more than this was D-Bus, but we didn’t get a chance to speak to the representative. We’d love to develop a smart home that learned how to make optimum use of the heating/cooling options available to it in order to maintain a comfortable inside temperature.
Time well spent at the Home Show
Overall, a productive but tiring day.
I can’t wait to get started on the ‘design wall’ so we can start to see what we are aiming for. It’s going to look like one of those evidence walls you see in the crime shows with pictures, sticky notes, pages, etc surrounding the floor plan and elevation drawings . At the very least, it will be a talking point for visitors.