SIP manufacturer Formance has released a technical bulletin for designers focused on how to specify or calculate Formance panel performance for certified Passive House projects. The bulletin is based on a report by Sustainable Engineering.
The values provided on the Formance website (for an overall wall assembly with air surface film resistance and cavities) can’t be directly entered into PHPP. The bulletin includes tables that can be used to calculate SIP construction performance.
The main variable left when calculating panel performance is the timber fraction in the panel. Based on several Passive Jouse projects, I’d recommend starting with 15% timber in the panels. This should give some margin once you subtract the timber around windows and slab edge that are accounted for in the thermal bridge calculation.
I highly recommend downloading and reading this bulletin.