In researching alternatives to stick-built wood framing for a proposed 2,000 sq. ft., two story plus full basement house I’ve run across Eco-Panels. The house would be in zone 5 on a narrow lot, 25′ wide. 
These SIPs are differentiated from most by their use of closed cell polyurethane foam in between the OSB skins. Sections are 4′ wide or less as needed. They make 90 degree corner sections and a 130 degree section for bay windows.
They’re available in nominal 4.5″, 6″ and 10″ thicknesses with corresponding increasing R values. The standard height is 8′ but they can supply up to 10′ high sections without joints in the skin of the section.
The product is made in Mocksville, NC, and by a licensee in Tennessee as well.

Curious if any readers have used these and the pros and cons for them.
I would have to get a one hour fire rating by laminating X rock on both sides of these SIPs to meet code unless I want an unappealing 15′ wide house.

thank you
Paul White