The eight-star InsulLiving home in Wallan, Victoria

A new network for builders is aiming to provide readymade packages for green homes to the lower end of the housing buyer market, with a demonstration home – the InsulLiving home – launched at the end of last year at Wallan, about an hour north of Melbourne.

The Independent Builders Network currently has membership of around 145 builders, who collectively construct between 500 and 700 homes a year, so the potential to influence a growing number of consumers is huge, according to spokesman Tim Renwick.

Renwick says IBN is training all its members in South Australia, Tasmania, Victoria, New South Wales and Queensland in the InsulLiving products and method, as well as other sustainability-enhancing aspects.

Tim Renwick
Tim Renwick

The group suggests a package of green products pre-sourced under a group buying arrangement. For example, IBN members encourage home buyers to install photovoltaic systems, which, in combination with the other initiatives, can achieve close to zero net energy use. This lifecycle financial case is the one IBN is pitching to potential buyers.

“It is most effective to promote green building by presenting the consumer with solutions to a financial problem,” Renwick says.

“They have the cost of the house and land, and then they have the budget they will need to live in it, and we are trying to push that side of the equation with buyers. If we say, ‘This [energy-saving item] is standard in the cost, and your energy bills will be lessened by X amount,’ that makes sense. People do want to be green, but they don’t want it to cost more.

“My job is to get the average mum and dad’s house to be a sustainable home – it’s Henry Ford thinking.”

Products have been tested by organisations such the Queensland University of Technology, which also did a Living Energy Rating of the first completed InsulLiving home in Burpengarry on the Sunshine Coast.

The research found that the house used 48 per cent less electricity than the average South-East Queensland home, provided thermal comfort without mechanical heating or cooling for 87 per cent of the year, and had an effective NatHERS rating of 9.5 stars.

Another home built in Tasmania, where heating is a priority for much of the year, showed that the occupants reduced their annual power bills for heating and cooling from $1200 to $500 a quarter compared to their previous home.

The IBN was founded in 2009 by Kevin Renwick, former owner and chief executive of Hotondo, one of the world’s largest building franchises. Hotondo also constructed the first green home for Sustainable Energy Australia, under the direction of Rob Gel, in 1993. The experience from that project shaped the IBN approach.

Another builder member, Norm Duell from Seymour, is currently working with an architect to design and construct a home based on the European PassivHaus standard.

Competing with major volume builders

In addition to promoting eco-homes, the other aim of the network is to provide a lower cost option than major volume builders. Being part of the network means builders can benefit from sharing knowledge about products, methods, marketing and research, as well as group-wide supplier arrangements for key products.

IBN has a head office staff of nine, across roles including training, marketing, design and procurement.

Renwick estimates the network’s members currently construct a combined total of between 500 and 700 homes a year, and hopes this number will grow with uptake of the eco-home approach by buyers.

“If we made five per cent of all new homes being built in Australia net zero, imagine what a massive difference that would make to the national carbon footprint,” he says.

The Wallan InsulLiving home

The Wallan InsulLiving home was officially opened by the former Victorian environment and climate change minister Ryan Smith.

Built by Marcel Mott of DTC Family Builders, the home features a range of materials expected to lead to superior performance.

The home uses prefabricated InsulPanel and SolarSpan, marketed as 100 per cent recyclable, which replace framing, rafters, brickwork or cladding, internal plaster board, ceiling liner board and insulation with a single product.

Because prefabricated products are rapid to erect and require fewer trades on site, Renwick says the speed of construction translates into immediate savings for buyers, as they are not paying rent or mortgage payments on the current home for as long while waiting to move in.

The wall panels have a BlueScope steel shell and a polystyrene infill with pre-installed channels for services and electrical cabling. Roof panels are Colorbond above the insulative core with steel on the inner face. Both products are rated 29 for Bushfire Attack Level, making them suitable for Ember Attack Zones such as Wallan.

Both products are fully recyclable at end of life, and are manufactured using non-toxic raw materials and a high degree of recycled content. All waste from the cutting of panels to size on site is also recycled.

Other sustainability features include promoting light coloured roofs to buyers and making certain items standard, such as LED lighting, solar hot water, double-glazed windows, rainwater capture and reuse, purple pipe grey water reticulation for toilet flushing, and low VOC paints and interiors.

The Wallan home also showcases an Australian-made solar skylight for interior lighting. The Illume skylights do not require an electrician to wire them in, and can be used for in-board rooms and small spaces such as butler’s pantries, and also to create window-like daylighting in a party wall. They can also be hard-wired into a domestic solar generation system feeding into the grid and home circuits, and provide night lighting as well.

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  1. I am wondering what level of thought has gone into the materials intensity of the materials you are using and future health impacts. How is all of the polystyrene you propose using manufactured, where and what is it made from?
    My understanding is that ” Extruded polystyrene is usually made with hydrofluorocarbons (HFC-134a), which have global warming potentials of approximately 1000–1300 times that of carbon dioxide and that discarded polystyrene does not biodegrade for hundreds of years.
    Polystyrene foam is a major component of plastic debris in the ocean, where it becomes hazardous to marine life and could lead to the transfer of toxic chemicals to the food chain and is abundant in the outdoor environment. It can be lethal to any bird or sea creature that swallows significant quantities.

  2. Hi Willow,

    I read your article with great interest and I was wondering if HydroHeat could be of any help to reduce energy for these particular homes using the latest technology in hydronic gas heating which can integrate with solar. Low temperature floor heating assists in reduced energy consumption and emissions with a high level of comfort.
    I could also get in contact with Marcel Mott of the Wallan project.
    Thank you for the article. This is the path/direction we need to take.
    Regards, Jan Voorham