Sustainable House Day: Comfort doesn’t have to come at a big cost
Willow Aliento | 1 September 2016
Ahead of Sustainable House Day, being held across the country on 11 September 2016, we’re taking a look at some of the best homes on display.
For just $20,000 building designer Simone Schenkel and her husband managed to turn a brick veneer apartment with a miserable 0.8 NatHERS rating into an energy-efficient, thermally comfortable 8.4 star property.
The Gruen apartment, in the outer Melbourne suburb of Ringwood, is a “typical” ’50s-’60s vintage apartment, one of four in a low rise building.
Schenkel says the renovation did not need approval from the strata body, as almost all the changes have been on the inside aside from replacing the windows with imported thermally efficient double-glazed UVPC ones.
They also added a 1.5kW solar system on the roof at the north-facing rear of the property.
The internal layout was changed to convert the two-bedroom, one-bathroom floor plate into three bedrooms and two bathrooms. A new kitchen and bathroom from IKEA was installed, and all lighting changed to LED throughout. Appliances were upgraded to energy-efficient ones, and all taps and fixtures upgraded for water efficiency.
The walls, which had no insulation, were renovated seven years ago, Schenkel says, and she and her husband did the work of demolishing and removing the old plasterboard. In scouting for quotes for replacement plasterboard and insulation installation, she looked for the cheapest price.
This turned out to be a mistake, she says, as the installer left gaps everywhere that she and her husband then subsequently fixed.
Over the subsequent years she has now found good people to work with on projects that can be trusted to do the job well.
She says old homes like hers are hard to get to a good level of air tightness. A blower door test has not been done on the home, but for a new build that is something she would want to see done.
While the house has an 8.4 rating according to FirstRate5 software, she says it is more likely actually 7 to 7.5 stars, as the rating tool does not account for the gaps she knows exist in terms of insulation in the corners and the roof.
In terms of water heating, the apartment is still using the ageing gas system, and Schenkel says they will wait until it reaches the end of life before replacing it, potentially with solar hot water, although roof space is limited to the north so it would need to go on the east.
A new ducted heating and cooling system has been put in, and there is an existing split system also. Schenkel says she would love to have hydronic heating, but it is too hard to retrofit.
She found when looking for quotes for the ducted system that most suppliers disregarded what she told them about the home’s improved thermal performance and quoted for over-engineered systems with far more outlets than would be actually needed.
One of the suppliers finally did listen, and advised her to go for the very smallest system possible. Schenkel says the system has only five outlets, and the home’s performance is such that it only needs to be on for a few minutes and then left switched off for a few hours to keep the home at a comfortable 17 to 18 degrees in winter.
“In summer the house stays cool for a long time,” she says. They installed a blind on the western window to reduce heat gain, so even when it is 35 to 40 degrees outside, the interior will be around the early 20s early in the day and then rise to around 26 or 27 degrees. So the airconditioning only needs to go on for a short time at night to cool the house.
In terms of energy bills, Schenkel says that when they moved in as a childless couple that worked full time away from home, they were using an average of 21.5kWh. Now, she works at home full time and there are two small children in the house, with all the added laundry that entails, and energy use is down to 6.2kWh.
She says they would be spending a “fortune” on electricity if it were not for the upgrades. As it is, the solar PV attracts a 65 cent feed-in tariff per kWh, so in summer and spring the household makes a $10 to $20 profit on its power, and in winter pays around $10 a month.
Schenkel says design and sustainability are her passion. She studied to become an architect in Germany, and when she moved to Australia in 2007 thought initially things like double-glazing that are standard in her home country would not be needed here.
“A lot of my education was around passive design and energy efficiency,” she says.
She is a registered building designer, who has been running her own business Gruen Eco Design for three years and is making sustainability in design her main focus.
She says her clients want to hear about her experience in improving the property.
Agents that have come through the property have told Schenkel this type of sustainability is what buyers and tenants are looking for nowadays.
She says their valuations showed that the couple has easily made a $200,000 profit in terms of value uplift in the seven years they have owned the unit. It could also attract higher rent than the average Ringwood apartment, she says.
“People appreciate that they don’t have to pay many bills,” Schenkel says.
Her motivation for opening the home for Sustainable House Day is two-fold. First, to show people this type of improvement can be done.
“Most people can’t afford to build a new home. So people live in these terrible draughty homes.”
She says she finds it sad that people will spend money on upgrading a bathroom, but not on insulation.
“When I wanted to do the renovation, a lot of people thought I was over-capitalising,” she says.
“The home was the typical Melbourne home – draughty and not pleasant. But it turned out to not be so expensive to do, and the home is now so comfortable.”
The second reason she is opening the doors is to show people why it’s worth it, so they can feel the benefits.
“There is such a difference in how you live and how you feel in your home,” she says.
She and her husband are now planning their next project, which is to build their own home. They are looking at the more affordable outer suburbs for a site to build a display home that will showcase sustainability while they live in it for a year or two, Schenkel says. Then they will look to sell it and build again.