We built a SIPS home a couple of years ago. The architect doesn't necessarily need any experience in SIPS as the technology can deal with standard plans. We sent our plans to the SIPS company who made a few minor alterations to improve load bearing distribution, roof pitch etc., but the architect approved plans are essential to get through planning. I can't remember the price off hand but will go through records to find out. The architect was also required to visit the site several times and sign off on things such as services and other buildings regs. The biggest pain we had was finding a competent company that could build a standard concrete platform to specification. The house itself wasn't a problem and was completed and ready to move into in only 40 days.