How does Passive House certification work? Does one have to go to a PHIUS certified architect to get a house design/plans and Passive House certification? Can a non-PH architect get house plans certified? If so, by who? PHIUS? What are the approximate costs for PHIUS review, consultation, and certification?
Passivhaus certification for a project requires that the plans be analyzed and and submitted to PHIUS by a Certified Passivhaus Consultant. The design can either be by a TEAM of a certified PH consultant & a non certified architect or by a PH certified architect. Personally, as an Architect and a PH certified consultant I find that it would be difficult and time consuming to coordinate with an architect who does not have a good, solid understanding of the concepts, however, I think a good PH consultant can give the Architect and Client a good overview of PH principals in about 4 hours.
The real tough part is the coordination of the design details with the PHPP (Passive House Planning Package). As a design/builder I can tell you that when I am designing I have both my CAD program and the PHPP open to determine the optimal outcome to maximize efficiency and minimize price.
I would think that the the client should be prepared to spend more for an untrained architect as there will be a learning curve and it is likely that there will be considerable redesign to bring the iterations of the plans into compliance with PH principles.
As far as the costs, that depends on the project and the team. My personal recommendation is that the best, most cost effective approach is true design/build, where the architect, PH consultant and builder are one entity and have one point of responsibility to the Owner.
If you want to pursue separate architect, PH consultant and builder, then I would recommend a very intimate process where the team is assembled day one and the Passivhaus Consultant is responsible for orienting the team to PH principles. I cannot stress how important the builder is in all this. You can have a great design and an efficient PH concept, but without a builder grounded in real world details and a deep understanding of PH concepts, the entire project can spin out of control, because of the high level of quality and attention to detail that is required to implement Passivhaus techniques.
I hope this helps!