There are a number of different manufacturers, criteria, and options when selecting ultra-low energy, high performance windows. If a project requires the Passivehaus and/or Passive House performance standards, Alpen is the only American-made window with both PHI (Passivehaus Institute) and PHIUS (Passive House Institute U.S.) certifications.
Studio St.Germain's Midtown Passive House project was the first Certified Passive House in the state of Colorado and Alpen was used for the project. For more information on this innovative product, please visit the Alpen website.