My concern on SIPS is my own ignorance. That to a large extent is because they don't seem to aim at the professional contractor market... which to me suggests that it isn't commercially competitive.
I see the systems used in Architect led projects where the end result seems very expensive to me... so I (cynically?) suspect that they do target the public at self build exhibitions, and some architects who are , unlike designer-contractors, not so aware of the real cost.
Hence quotes I have seen on here and elsewhere will exclude steels that may be needed, interfaces, perhaps even insulation targets.
Thus beware.
absolutely.
To know how it works out in real life the pros on here need to know more.
The self builders who have used sips may well be very happy with the results, but have probably not got experience of other ways. But they will advise of what, if anything, to beware of.
My gut feeling suggestion is to you, as a self builder who wants lots of hands on and economy , is 'stick build'. It fits, and is sympathetic to newbies*... it offers second chances. But you won't see that at exhibitions.
* that would include theoretical me if without builder help. Strip footings, stud build, timber cladding, timber roof, metal sloping roofing, or tiles.