Today we had the final blower door test at the Passive House in the Woods project done. The result is a wonderful 0.26 ACH50, or 70 CFM of leakage at 50 Pascal pressure. Find more details in my article on the Passive House in the Woods website.


  • Steve Tjiang says:

    0.26 ACH50 — That’s really impressive. My house in Palo Alto (northern california) is being sealed now and like to hear about how you achieve such tightness. We’ll be doing a blower door test on Tuesday, October 5.

    • Tim Eian says:

      Some thoughts on air-tightness:
      In general, thorough detailing in the planning phase, and thorough execution and supervision during construction.
      Clear designation of the air-barrier. Continuity of the air-barrier.
      “Simple” assemblies. Easy-to-follow instructions on site. Education of the executing contractors and subcontractors.
      Avoidance of “weak” assemblies that do not lend themselves to air-tight construction (e.g. no cavity wall framing).

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