Old Home Foundation Structural Integrity Analysis for Underpinning and Addition

I am in the early stages of a basement remodel in an old 1933 home in Lakewood, CO, that I own. Being in an old house, the unfinished basement ceilings are approximately 6.5 feet in height and so I am considering digging the basement down to perform an underpinning of the foundation. I may also want to expand the foundation to support a home addition where I'd like to either add an egress window or walkout door to facilitate a basement bedroom/living area. Before starting the remodel, I'd like to have the structural integrity of the old foundation assessed to see what can and cannot be done.