If you're adding a second floor there's the weight of all the new materials. How the existing wall will handle it is a question often worth having an engineer answer. Seems pretty obvious, but if you're a 'framing contractor' you know this already.
The only thing in a wall that has to be checked to handle a second floor are the headers. And that can be answered by an architect too.
Any point loads that need to be addressed will be on the plans.
Last edited by Joe Carola; 06-14-2012 at 10:47 PM.