Unfortunately, many places, including Oregon, are moving towards copyrighted building codes. This means that accessing the laws governing construction codes is a pain. The state allows you to view them online, but only through either a proprietary electronic reader or through locked PDF files. Printing and copying and pasting are turned off.
Luckily, the good people at public.resource.org are taking a stand. They believe copyrighted codes are inimical to democracy and are acquiring and releasing codes for free, without restrictions, and preparing for any legal challenges to their position. They have made copyrighted Oregon codes available here at archive.org.