House addition; engineering required

We are adding to a home in Camas County, ID, which adopted the 2018 IBC a few years back, only to discover that it requires ALL buildings over 200 s/f to be engineered due to snow and wind loads. I need a quote on engineering, to include #3 seismic zone, 115 psf wind load, and 100 psf snow load. I have plans already by a local draftsman, to be stamped by a licensed engineer. Requirements attached.