My basement has about 2.5 ft of concrete along the wall. The reason is that the outside is a slope/hill and that 2.5" depth is just dirt. I like to install a patio door to my backyard 60x80 which is a typical size. My question is if I cut the concrete in the bottom of the wall, what do I have to consider?
My picture below:
For example, do I need to build a concrete foundation underneath and extend it out by digging the clearance area outside? How do I deal with the king stud (just two 2x4 enough?) and how is the requirement for header?