We did  gut renovation two years ago, currently have a leak in basement from side of house and the house shakes on windy days, it’s a 3 family house detached, 20x60. had many issues come up, more recently had walls opened for spray insulation, and noticed the corner post is rotten from first to second floor. Same contractor recommended we have the post and studs reinforced from the outside, which I would pay for and he would pay for replacing the siding insulation styrofoam and water proofing…. This job is not cheap and we aren’t sure if this will fix the two issues we have now… we originally thought our gut renovation would’ve addressed everything from the foundation and above…. During construction the foreman told me and GC all the wood was fine…  Apparently after the work, now we are having issues… GC is trying to work with us, was wondering what are thoughts on fixing and options to address

will add more thoughts as they come to me… we did have water issues before construction and GC was aware, the one corner had a lot of rotten wood when they opened it up… the internal structure was sistered and reinforced from basement to third floor. What are chances house would collapse..?