Bonsai Design Build sets high mark for airtight assembly: blower door test reveals Passive House-level performance

January 2015 –

Bonsai Design Build’s new construction work at the Lipan Street Cottage wrapped this month with the home’s final inspection and blower door test. The results are in, and they’re spectacular: built using SIPS, Siga Tape and, of course, Alpen high performance fiberglass windows, the Lipan Street Cottage blower door test revealed an astounding whole-building infiltration of ACH 0.59 @ 50 Pascals.

Causing the building energy rater to remark, “I’ve never tested a house so tight,” the Lipan Cottage blows past all Energy Star construction standards and comfortably meets even the most stringent airtightness requirements of the Passive House approach! Congratulations Bonsai Design Build, AE Building System and all of the design and construction team!

Alpen’s partners at AE Building Systems created this photo documentary to share the design, demolition and new construction work that went into the Lipan Cottage project. Energy efficient construction and beautiful design breathes life and architectural appeal into this small, forgotten block in Denver’s “LoDo” neighborhood: