For mechanical engineer Jon Iliffe and homebuilder Baden Brown, who both live on New Zealand’s North Island, the urge to create a line of high-performance homes began percolating about a decade ago. They kept talking as the years went by, until Iliffe returned from an 18-month stay in Europe, where he did contract work for Rolls-Royce and had an opportunity to study Passivhaus design and see homes built to the standard.
Iliffe and Brown, joined by their wives, have since channeled their enthusiasm for energy-efficient homes into the launch of a development company called eHaus that recently commenced construction on a 2,422-sq.-ft. prototype home in Wanganui, on the North Island’s west coast. Iliffe told GBA that the four-bedroom, two-bath house will not quite meet the Passivhaus performance standard, “but the build will be pretty close.” (Both men are training in Passivhaus design at Unitech Institute of Technology in nearby Auckland.)
Creating a new market
The exterior walls of the prototype feature ECO-Block insulating concrete forms along with double-glazed, argon-filled aluminum-frame windows from Open Building Solutions, a New Zealand company. The windows – which were pressure tested at 50 Pascals before they were installed – feature a thermal barrier, sandwiched between the outer and inner sections of the frame, that is designed to prevent both heat transfer and condensation. Much of the window coverage is, of course, on the north side of the house, where passive solar gain from the Southern Hemisphere sun can be maximized.
The house will be equipped with a heat-recovery ventilator, a solar hot water system, and accommodations for a photovoltaic system. Weather conditions in this part of New Zealand tend to be relatively mild, with a mean temperature, on the Fahrenheit scale, of 54, a high of 90, and a low of 27. Annual rainfall averages about 34 inches. The eHaus prototype will include a water recycling system designed to meet all of the occupants’ water needs except drinking and cooking.
Iliffe told the Wanganui Chronicle, a local newspaper, that he and his partners understand eHaus will be catering to what is, at the moment, a niche market, but that stringent energy efficiency standards such as Passivhaus suit their personal philosophy about energy conservation.
“Making money isn’t the be-all and end-all for us,” he said. “Building low-energy houses really fits with who we are as well.”