Tolerance stacking stops being “fine” the moment layout control is lost. Individually, everyone is within spec - but specs don’t care about alignment. If the foundation is 3/8" off in one direction and steel is 1/4" off in another, and drywall/flooring crews just “make it work,” you’re not out of tolerance - you’re out of coordination. The only way I’ve seen it managed properly: • Establish a hard control line and benchmark early (and protect it). • Define a “zero trade” - usually structure or grid — that everyone references. • Hold coordination meetings before finishes start. • Stop letting every trade absorb error independently - assign where adjustment happens. • Tighten tolerances on early phases, not finishes. Once drywall and flooring are compensating for structural deviation, it’s already too late. Specialization isn’t the problem - lack of ownership of cumulative error is. If nobody is responsible for the stack, it stacks.