When we last checked in on Passive House in the Woods, a project in Hudson, Wisconsin, it was early May, exterior insulation was about to go up, and the construction crew was probably more than ready to welcome summer weather. Things stayed on schedule. By the end of last month, construction had been completed and the house was open for public tours. Last Thursday, the project received certification from the Passive House Institute U.S.
The house – two stories, with three bedrooms and 1,940 sq. ft. of interior space – was guided to completion and Passivhaus performance standards by Tim Delhey Eian of Minneapolis-based TE Studio, and the project builder, Morr Construction Services of Shoreview, Minnesota. The client, Gary Konkol, a general-practice physician, explains in a post on the project’s website that he was inspired to pursue the Passivhaus standard in part by news reports, Passive House Institute’s book “Homes for a Changing Climate,” and Eian’s enthusiasm for the standard and the construction quality it entails.
A prototype for carbon-neutral performance
Passive House in the Woods, or PHitW, was constructed with 11-in. insulated concrete forms and an exterior-insulation and finish system that brought the overall R value of the walls to 70. The slab, sitting on 12 in. of extruded polystyrene, is designed to R-60 and the flat roof, with an average of 14 in. of of polyisocyanurate insulation, to R-95.
The building also is equipped with solar hot water and a 4.7 kW solar power system, which is expected to cover the home’s predicted 4,200 kWh annual usage and feed power back into the grid. The house has four doors to the outside (see comments below), including a front entry door in the front canopy area, one opening to the deck on the first floor, and another on the second-floor landing (known as “the plank”). A common steel-structure stair connects all levels to the ground and a rooftop terrace.
Though he was not at liberty to discuss the final construction cost of the project, Eian told GBA that the “up-charge” to bring the building to Passivhaus performance standards was between 15% and 20% for this project, although, he added, “we feel that we can push that closer to 10% with some efficiencies in the future. I can also tell you that the cost of the home is perfectly in line with custom architect-designed homes in our area. It is more a matter of priorities than cost, once we are designing a high-quality building.”
“Rather than a high-end showcase,” Eian said, “we look at it as a prototype for CO2-neutral operation.”