Check out this article in the Clackamas Review, detailing the Passivhaus movement that is slowly catching on in the Portland Area. Hailing from architecture hot-beds Germany and Austria, the Passivhaus concept is pretty straightforward: “insulate a house so well that it’s airtight, then heat it with a small electric heater or heat exchange pump. The result: potential energy savings of more than 70 percent. As U.S. Rep. Jay Inslee, D-Wash., wrote to the recent Passive House Northwest conference, ‘It is incredible to think that you can heat your entire home with as little as a hairdryer!”’
Sound too good to be true? The new wave of home construction requires extremely careful inspection – every screw, window, door, siding segment, and beyond must be completely air tight to make sure the Passivhaus registers no more than 0.6 air changes in an hour (a typical Portland house will register 20-30 changes/hr, while an efficient new Energy Star-compliant home will have around 7).
There are only three passive houses in Portland, but they’re attracting a lot of attention due to their modern design, comfort, and sustainability. In one house, the “walls are about 12 inches thick. The stud cavities are filled with a blown-in fiberglass insulation that eliminates gaps found with typical batt insulation. The exterior wall is wrapped with a three-inch blanket of rigid polyiso insulation. The concrete floor slab is insulated with nine inches of expanded polystyrene insulation, and a vapor barrier helps maintain the airtightness.”
