Second floor addition that doesn’t rely on original first floor foundation?

Second floor addition that doesn’t rely on original first floor foundation? Would it be possible to build a second (half) story addition using full-span attic trusses, resting on beams, with those beams resting on new piers set immediately outside the current first floor walls? Visually, imagine a post-built pole barn over the top of a ranch with after its entire roof, rafters, and even ceiling joists are removed. Ignoring any cosmetic concerns of “it would look dumb having posts along your outside walls”, is there a reason it wouldn’t be feasible? Original foundation can’t support a second floor. This avoids expensive underpinning. Beams can certainly be calculated to hold the weight of attic trusses, the living space inside them, and the roof. First floor interior (and exterior) walls would not be load bearing. Roof might overhang the first floor by a good 3 ft because of piers being necessarily farther out, but again, ignore cosmetic concerns for now. First floor walls could be connected to new trusses without becoming load bearing, making the entire structure one rigid structure. Thoughts?