Passivhaus Windows, Made in the U.S.A.
Two small California companies nab the first domestic window certifications from Germany’s Passive House Institute.
By Paula Melton
and , two small California manufacturers, have become the first U.S. companies to certify windows through the Passive House Institute (PHI), based in Germany.
Casagrande will reportedly begin production of its PHI-certified Synergist model, a wood casement window, this summer. The Synergist window is certified with a whole-window U-value of 0.139 (R-value of 7.2).
Wooden Window expects its(which currently includes one fixed and one operable wooden window, both with aluminum cladding) to start rolling off assembly lines in the next few months. Both models boast a whole-window U-value of 0.137 (an R-value of 7.3).
Any product that contributes to the stringent overall energy requirements of the Passive House building standard can be used in a Passive House project—in theory. However, the Passive House Planning Package (PHPP) modeling software used to assess whole-building energy performance requires certain data not usually measured or reported by U.S. window makers, who typically use the National Fenestration Rating Council (NFRC) system. Most North American project teams have importedfor Passive House buildings.
Two U.S. window manufacturers—firstand then Marvin—have achieved certification for some window models under the separate Passive House Institute U.S. (PHIUS) program, which rates windows by climate zone. . The two window certifications are not the same, but both Passive House programs base their certifications on modeling only; NFRC’s program requires physical testing as well.
For more information, download the press release from the.