Here is a link to the Yuba City building department:
For additional information search "emergency egress window requirement"
My thought would be that if the window was designed to open originally then it should open now. If it was made as a single pane of glass and not intended to open then maybe not. I say maybe because I do not know if the owner replaced a window that should open with one that does not open (a less expensive option). If so there may be safety concerns in the case of emergency.
I will assume it is supposed to open but does not now. Make sure the owner is aware of this so when you leave there is no mistake and you have to pay from your deposit to fix it. You should have completed some sort of move in checklist/form that describes the condition of the home when you moved in (photos are great too). Either way I would send the owner an email or note (something in writing) that states the window does not operate properly (describe what is not working) and it never has since you have been in the home.
Brian Wilson, Realtor
Call the local fire department; I'm sure they will be able to comment authoritatively on your question. Obviously, having a window that allows egress during a fire can be a life or death issue.
You should also ask about the new Carbon Monoxide sensor law that went into effect in July.