Walking the talk in Perth
Alex lives in Perth with his wife Chiara and runs life cycle assessment company eTool* (see 10 tips for a low carbon renovation). He loves sharing his knowledge about sustainability and helps clients implement the most energy efficient and cost-effective sustainable design features in new and retrofitted homes. But what does he do in his own home?
When Alex came to buy his 1980s townhouse in Perth almost 4 years ago, he was excited to finally get a chance to implement all of his sustainable ideas and features.
Alex’s house is a 100m2 townhouse on two stories with 3 bedrooms and a small paved garden out the front and back. Alongside all of the sustainable features, Alex uses the garden to grow fruit and veggies including tomatoes, passionfruit, salads, herbs and potatoes which are all helped along by his DIY worm farm inside the raised beds.
Using Free Life Cycle Assessment Software to Help Guide You
Before deciding which sustainable features to implement in his house, Alex ran a life cycle assessment (LCA) on the whole building using his company’s software, eTool (LCA®) . Using eTool’s free online tool, Alex could compare all of his ideas such as solar PV, heat pump hot water, insulation and natural finishes to see where the best savings could be made both environmentally and financially. Understanding how the house performs as a whole and how it will continue to perform throughout its lifespan, made Alex’s decisions so much easier.
Alex implemented the following sustainable features and saved 102% carbon emissions against the average Australian three-bedroom dwelling, making his house zero carbon!
Project Costs – small budget, big result
Alex planned his retrofit on a very tight budget. Altogether, the retrofit cost less than $8000, which was actually less than the cost to renovate the upstairs bathroom. As part of the life cycle assessment, Alex received a financial analysis of his sustainable choices, which calculated that all of the investments have a payback period of six years or less.
While the average house has grown to over 220m2, Alex chose to stick with something smaller and much more functional at 100m2 so the environmental footprint of the home is halved. Fewer building materials, less requirement for air-conditioning, lighting and even cleaning and maintenance make it a lot more home-owner and environmentally friendly. Also, local amenities such as the park across the road and shops and pubs are within walking distance. And as it’s a townhouse, it should last a lot longer than the average detached dwelling; whatever went into building it will get far more utilisation.
Heating + Cooling
Rather than using reverse cycle air-conditioning like many of his neighbours, Alex installed ceiling fans, which alongside the insulation, shade cloth and cooling vegetation keep the house comfortable throughout a hot Perth summer. In the winter, Alex heats the house using a high efficiency wood pellet heater that burns small amounts of compressed waste wood. Not only is the fuel renewable and low in carbon, but it produces a beautiful natural heat with almost no smoke.
Hot Water Heat pump
A 280 litre heat pump system was an ideal solution for Alex’s house as it sits on two storeys. The main advantage of a heat pump system is that it extracts energy from the surrounding air to heat water using only about one third of the energy of a standard electric storage system.
By monitoring energy usage in real time, Alex understands which appliances and devices are demanding the most energy and can adjust his behaviour accordingly. The previous owner used 22 units of energy per day, which is pretty average for Perth; however, Alex was able to reduce household usage down to just 6 units a day.
The 2.6 kW solar PV system takes advantage of Alex’s north-facing roof. The system produces more energy than the house needs, feeding the excess power back into the grid and generating around $1400 a year of income. One of the main advantages of a solar PV system is that it offsets carbon intensive grid electricity, which is particularly high in Western Australia.
Replacing the 30-year-old ceiling insulation helped reduce the flow of heat in and out of the house, improving the interior temperatures in both summer and winter. Alex reused ceiling insulation batts from a friend’s house that was being demolished in the neighbourhood, saving a bit of money and preventing unnecessary landfill waste.
During the summer in Perth, the walls of the house can get extremely hot, causing the house to overheat. Alex covered the west facing wall with a shade cloth which reduces the external wall temperature by a huge 20 degrees from 65 to 45 degrees on the hottest summer days.
*eTool is a life cycle assessment software company that helps home owners understand and lower the environmental impact of their new and renovated home designs. The company works on low carbon home designs every day and has put together our ten tips to help you renovate sustainably while maintaining the balance between capital outlay and return on investment.
For more information about Alex or eTool, please visit the eTool website.