I am developing a 4-story, 24 unit, 20,000sf multifamily building in Minneapolis (Climate Zone 6A).  We plan on pursuing PHIUS certification. 

Can anyone recommend a mechanical engineer with multifamily passive house experience that would be willing to consult/advise during pre/schematic design? 

I have a local mechanical engineer who I have worked with before and plan to use to produce the pricing and permitting set.  They have significant multifamily experience but not passive house multifamily.

I am in need of supplementary services to advise, point us in the right direction, and help confirm/refute some inbound hypothesis for the project.

Any suggestions?