T.J. Kirkpatrick, Deseret News
Induction cooktop in "passive" home uses a fraction of the energy of an average home.

SALT LAKE CITY — From outside, the home of Joseph Turner and Rebecca Guymon stands out from every other house in their established Millcreek neighborhood — not just because of its ultra-modern exterior and sleek European lines, but also because it represents the latest in new-age design in an otherwise old-school setting.

Turner and Guymon bought their World War II-era property a decade ago with the intention of making upgrades over time. Trouble was, time came, and they updated "little bit by little bit," Turner said.

"Then we decided that we'd kind of done enough and wanted to expand," he said. After discussing some proposed changes with an architect, they decided it would be more cost-effective to just "start over."

So they flattened the original house, leaving nothing but a couple of trees on the property, and embarked on constructing their dream home.

"We felt it was imperative to have (the new house) be a little more 'green,' and we wanted new and modern, open and spacious," Turner said.

Using those parameters, they enlisted the expertise of Salt Lake City architect David Brach, who specializes in net-zero energy building design and recently received certification as a passive home designer.

"(The passive house concept) was an idea that Dave brought to us," Guymon said. "He said, 'This is going to be the most comfortable house, and it's going to save you a lot of energy.'

"We were like, 'That sounds great to us.' "

The passive house concept represents the highest level of energy efficiency, with the promise of cutting heat energy consumption of buildings by up to 90 percent.

A passive house is a well-insulated, virtually air-tight building that is primarily heated by passive solar gain and by internal gains from people and electrical equipment, according to the website of the Passive House Institute of the United States, based in Urbana, Ill.

Passive solar buildings are designed to maintain interior thermal comfort throughout the sun's daily and annual cycles while reducing the requirement for active heating and cooling systems, such as furnaces and air conditioners, Brach said.

Completed in December of last year, the "Breezeway House" was among the first certified passive houses in the nation, according to Brach.

The home has about 2,800 square feet of living space, with three bedrooms and two-and-a-half baths. A 2.2-kilowatt solar array and hot water solar panels provide about 75 percent of the home's annual energy needs, Brach said.

The result is a house that uses about 10 percent of the energy of an average existing home and about 20 percent of the energy of an average new house built to code. In some cases, a passive house can reach net-zero annual energy consumption with the addition of a modest number of solar panels, he said.

To make the best use of natural light and reduce energy usage, the house was constructed on an east-west orientation, with most of the windows on the sides facing north and south, Brach said.

Since passive houses are built air-tight, they require a mechanical ventilation machine, which exhausts stale indoor air and replaces it with fresh outdoor air, he said. With this air distribution system, the homeowner can control the amount of air coming into the house and can filter it if desired, resulting in a high level of control over indoor air quality.

Brach said ventilating the house by opening the windows is also an option, just as it is in a conventional home. It is common to turn off the mechanical ventilation in the summer, Brach said.

The final construction cost for the house was about $175 per square foot, Turner said.

The home includes numerous unique features, including an energy-saving electric convection stove, space-saving custom-made kitchen cabinets and a stone patio with a built-in steel and canvas shading frame for outdoor dining and entertaining.

The upper level has bamboo flooring, while the main level employs glazed concrete for the kitchen counters and flooring — an ideal surface for the strictly regulated environment of the passive house.

"Because the house is so well-insulated, the floors never get cold," Turner said. "This floor is whatever internal temperature the house is … so we can walk on it barefoot, no problem."