Happen to be in the market for possibly the most energy-efficient house ever to be listed for sale in Minnesota? If so, green-home builder Ray Pruban's personal residence in St. Paul's Highwood neighborhood could become your place in the sun.

Built near the Mississippi River bluffs in a secluded part of the city that feels like it could be on the edge of a northern forest, Pruban's five-bedroom, four-bath rambler at 1017 Oak Bluff Circle is like no other home currently on the market — it was built as a demonstration project on how to meet the goal of "zero energy" use through the use of smart design and renewable energy systems.

Its debut during the September 2013 Parade of Homes garnered some media attention for Amaris Custom Homes and its message that "high performance" green homebuilding is not a dreamy goal. Rather, the builder claims, such super-efficient homes already can be built affordably and be as eye-pleasing as anything found at the end of a suburban cul-de-sac.

Now after two years of personally enjoying its features, Pruban has listed Minnesota's first U.S. Department of Energy "Challenge Home" for sale at $699,900 with a guarantee of zero energy bills as his company prepares to embark on an effort to expand the availability of such homes in the east metro market.

As founder and chief manager of Amaris, Pruban builds five or six very efficient homes a year on a custom basis. He constantly fights what he says are false and outdated impressions about them.

"I hear over and over again the belief that they have to be expensive," he said. "That doesn't necessarily have to be. We're trying to break down those barriers and show everyone that this is doable."

Take his current, 3,542-square-foot home, atop a steep, south-facing exposure to maximize its solar exposure.

It was built to meet the DoE's Challenge Home program (since renamed the Zero Energy Ready program), which was established to recognize builders who meet the goal of constructing homes so efficient that a renewable energy system can offset all of their annual energy consumption.

It not only meets those criteria, but also has the honor of being the state's only home built to meet the upcoming new LEED green homebuilding standards, dubbed Version 4, to be released in 2016.

The house scores extremely high on the industry standard Home Energy Rating System (HERS) index. The index rates a home's energy efficiency on a scale in which 100 represents an average home. A HERS of 70, for instance, translates to 30 percent less energy use than average while a score of 130 would be 30 percent more. A typical new home in Minnesota will garner a HERS of 80. A Pruban home is rated at a mere 3.

"Because of the solar, this house was designed from the roof down, the opposite of how it's typically done," Pruban said. "Everything humanly possible to promote energy efficiency has been done here, but all of it affordably. To get a new home down from a HERS of 70 to a 40 may add 5 percent to its construction costs, which can be recouped and then some over time through lower energy bills."

Once the St. Paul house is sold, Pruban plans to move into the model home at his newest development in Afton, called Trading Post Trail Preserve, where his company has six lots. After that, it will be on to Lake Elmo, where Pruban says he is going to put the market potential for his high-performance home concept to its stiffest test.

"Our Lake Elmo development won't be custom homes," he said. "Instead, we're going to design these ourselves for maximum performance and see for the first time in Minnesota how the market accepts this new kind of homebuilding."

Don Jacobson is a freelance writer in St. Paul. He is the former editor of the Minneapolis/St. Paul Real Estate Journal.