So, why should home buyers be interested in The Wander House, which the couple shares with their two daughters? "Let me count the ways!" Rosen exclaims. The home is built on an infill lot in the highly desirable Hintonburg neighborhood. "It's the third house we've lived in on the same block for last 12 years," Rosen says. The home was designed and constructed to the rigorous international Passivhaus standard.

Built with super-insulated walls, ceilings, and floors, the modern single-family home is air-tight and requires about 85% less energy for heating than a typical new home. The home also has a shallow geothermal ground loop, greywater-ready plumbing system, high-efficiency ventilation system, and heat pump hot water tank.

The realtor calls it:

The Ottawa climate, with its temperature extremes, not to mention an urban lot where site orientation is complex, posed significant challenges. "Still, if Passivhaus is the gold standard, we decided to walk the talk and show we could do it."

Initially, the Rosens considered using an off-site panelized prefab system. "The challenges of building during a Canadian winter are real," Rosen says. "The less time you have people working outside, the better." But the building partner wasn't ready, and the Rosens went with site-built instead.

Because of the home's Passivhaus design, heating demands are significantly reduced, Rosen says. "We didn't need to install any traditional large metal ductwork usually necessary for furnaces and air conditioning," he explains. "The only ductwork we have is for our ventilation system, which uses 3" flexible tubing easily run through the open web joists and inside 2x4 walls."