Is building a passive house more expensive than a standard house?
Yes, passive house construction is estimated to cost 10 to 15 percent more than standard building costs. That said, by slashing energy costs, passive houses save owners considerably over time.
Can an existing structure be converted to a Passive House?
Yes, conceptually, an existing structure can be retrofitted to conform to passive house standards. The process could involve building an outer shell around the entire house (wall and roof), but this isn’t always possible. There’s a more attainable standard called EnerPHit, a version of passive house design for retrofits of existing buildings. It, too, is a set of standards—including use of thermal insulation, high-quality windows, and ventilation with highly efficient heat recovery— that provide significant energy savings.
Above: To convert this 19th century barn in upstate, NY, to a passive house, architect Kimberly Peck clad the exterior in black corrugated aluminum with a standing seam aluminum roof. There are no windows on the front—that’s to keep insulation factors at their highest—but plenty on the back; see A Rural Barn Transformed for Modern Living. Photograph by Torkil Stavdal.
Is it possible to apply only some passive house approaches to a dwelling?
Yes, but that isn’t advisable. Passive house principles are interrelated: if a house is airtight, it needs a balanced ventilation system. If a house has continuous insulation, it will likely need very little heating and cooling.
Passive houses often gets confused with passive solar design (collecting and using energy from the sun to warm and cool the house). Are the two related?
Concepts of passive heating and cooling are part of the toolkit available to achieve passive house performance standards. The earliest projects studied by Adamson and Feist relied more heavily on passive solar heating methods, but the window technology of the 1970s and 80s was a liability: they allowed the sun to heat interior surfaces and were also leaky and transmitted the exterior temperature directly to the interior, which is no longer the case. The name stuck, even though passive heating is only one part of the equation.