"One of the last places you would look for an off-the-grid house is on a cul-de-sac in the Melbourne, Australia, neighborhood of Toorak. After all, the homes there are close together and hookups to the electric grid, as well as to water mains and sewer lines, are readily available. But David and Cate Sutton were determined to make their new house as self-sufficient as possible, almost as if they were living in the Outback.
Why? David, an engineer with extensive knowledge of building systems, wanted to challenge himself to produce what he hoped would be one of the greenest houses in Australia. And that meant generating electricity, turning rainwater into drinking water and dealing with sewage right on their quarter-acre lot. If that wasn't enough, he also hoped it would be "one of the most architecturally distinguished houses" in a country known for its excellent contemporary architecture.
The Suttons ultimately spent about $4.5 million on their 6,700-square-foot house. Of that, nearly $1 million went to green systems that won't earn back their cost anytime soon. David, 70, says he is at "a stage of life where I didn't want to do something in half measures. I wanted to push the boundaries on all elements of the building process."
The project began when the Suttons decided to move more than 2,000 miles from Perth, where David had built a successful engineering firm, to Melbourne, where their two grown daughters live. David had built or renovated eight previous houses, including a vacation villa in Italy, always employing architects because, he says, "their value far exceeds their cost." But this time, before he chose an architect he hired an environmental engineer, Nick Bishop, to write a report on the most meaningful green rating systems in the world. The report, which David has since shared widely with architects, engineers and builders, persuaded him to follow Passive House principles, which advocate making houses so well-insulated and so airtight that they require scant heating or cooling. In addition, he decided to follow the precepts of the Living Building Challenge, a program of the Portland, Ore.-based Living Future Institute that rates buildings not just on energy efficiency, water conservation and responsible sourcing of materials, but also on beauty, health and happiness, and equity (which includes accessibility).
But he also wanted the house to be salable when he and Cate, 68, are gone. So he next interviewed real estate agents, who recommended that, in addition to the living room, dining room and kitchen, there should be four bedrooms; three or four bathrooms; a media room; and a four-car garage. To "meet the market," David says, he made sure all those items were included. That made the house bigger than it otherwise needed to be, which isn't very green. On the other hand, building a house that is likely to be torn down is even less green.
Next David had to find a site. He spent months looking, online and in person, for a lot that met his aesthetic criteria and was also amenable to the green features he was planning. For instance, it had to have a long east-west dimension so that he could install 40 solar panels facing north, the correct orientation in the Southern Hemisphere, that will never be blocked by construction.
He eventually found a parcel he liked -- in the Toorak neighborhood, an affluent inner suburb. But there was a catch: The owners lived next door and would only sell the empty lot to whoever bought their house. So the Suttons purchased both properties, renovated the existing house, moved into it, and then sold it when they moved into their new house about two years later.
Next he gave a 50-page brief, outlining his myriad requirements, to a dozen of the city's best architects. After meeting with most of them, he narrowed his list to three before settling on perhaps the most experienced architect in Melbourne: John Wardle, the 2020 winner of the Australian Institute of Architects' gold medal. David liked the looks of Wardle's buildings, which include a spectacular architecture school at the University of Melbourne, and many ingenious but unpretentious houses.
The architect's firm, known simply as Wardle, turned out to be "the best possible choice," David says, "because they were very attuned to what we wanted to do with local stone and reclaimed wood and employing artisans whenever possible instead of buying products off the shelf." John Wardle says his firm had been conducting research into various green building technologies. This job "gave us a chance to pull all this research into a single project."
Though Passive Houses are often simple boxes with small windows, Melbourne's relatively moderate climate gave David more leeway. He asked Wardle to focus on creating the strongest possible design and let the contractor worry about making the building airtight. Wardle took that freedom and ran with it, creating a house with a nearly opaque street facade, giving the Suttons privacy, and a central courtyard that pulls the landscape -- and sunlight -- deep into the house. Part of the courtyard is filled with water to a depth of about two feet and is teeming with both aquatic plants and what David calls "healthy and very fertile goldfish." David's study is a double-height pavilion that emerges somewhat dramatically from the water.
One of David's many goals was to use natural materials found as close to the building site as possible. Making things like steel and concrete uses lots of energy, as does transporting materials long distances. The house's relatively soft limestone was cut directly from the earth near Mt. Gambier in southeastern Australia. The floors are tiled in siltstone from Queensland, also in eastern Australia. Wood for the exterior siding was recycled from a 150-year-old warehouse in Sydney, with some pieces as long as 22 feet. For the floors and interior paneling, including a canopy, or shroud, over the dining table, the architects specced Hydrowood from Tasmania. That's wood -- a eucalypt called Messmate, also known as stringybark or Tasmanian oak -- cut by underwater robots from trees that sit at the bottom of man-made lakes, which were formed 70 or 80 years ago as part of a hydroelectric project. "It produces pristine and beautiful timber," says Diego Bekinschtein, the firm's associate principal.
There was also an effort to produce details by hand rather than buy them factory-made. The balustrade where second-floor spaces are open to below is made of strips of rattan woven through tensioned steel wires by a cane furniture maker named Angelo Rusak of Camberwell Cane in Melbourne. The result is museum-quality installation that complements the Aboriginal art on the adjacent upstairs walls.
When it came to furniture, the architects created some of the key pieces, which allowed them to give the house and its contents a shared sensibility. The dining table incorporates what David calls "a linear Lazy Susan" -- a slot in which a couple of handcrafted trays slide from one end of the table to the other.
But if the house is beautiful, it is also a superb machine, David says.
Rainwater that collects on the roof is funneled into an 8,000-gallon underground tank and filtered until it is potable, with "a fresh, invigorating flavor," David says. The house is also hooked up to a municipal water main for backup.
But it is not connected to the municipal sewer. Instead, the house's gray water from sinks and showers is used to irrigate the gardens; black water from toilets is treated on-site and trickled into the ground.
The house's 18kw solar array meets all of its electricity needs in the sunny summer months. The array feeds batteries that can store 20 KwH. Once the batteries are full, the excess is exported to the grid.
But in winter, the Suttons buy electricity from the grid. For the house to be entirely energy independent, it would need many more solar panels and a larger, and prohibitively expensive, set of batteries, David says.
As it is, the solar panels on the roof and the batteries in the garage cost about $60,000 and return "a few hundred dollars a year" from the sale of excess power to the grid.
The photovoltaic system was a relatively small investment. The cost of plumbing, which would normally have been around $100,000 for a house this size, was more than twice that much, because of the filtration systems for rainwater, gray water and black water. Following as closely as possible the Passive House guidelines was even more expensive. The many triple-glazed windows -- and some as big as 10 feet by 10 feet -- cost about $350,000.
Sealing the walls carefully, adding extra insulation and airtightness membranes and installing an air circulating system added another $450,000. And fees for the architect and myriad consultants totaled about $1 million, David says.
Cate says she left most of the design decisions to her husband. "He's the art and architecture person in this relationship," she says. "I'm more about function."
For example, she asked that there be no glass in the bathrooms, because she didn't want to have to clean it. David, naturally, complied.
Its muted materials palette and modulated light, along with the sound-dampening properties of the heavily insulated building envelope, together make this "the calmest environment I've ever lived in," Cate says. "I find when I go out I just want to come home."" [1]
1. MANSION --- Off the Grid... In Suburbia --- A Melbourne couple wanted a home that was self-sufficient, as well as green and gorgeous. Bernstein, Fred A. Wall Street Journal, Eastern edition; New York, N.Y.. 14 June 2024: M.1.
