Down to the studs on a house from the sixties, including a new mechanical system and a reworked floor plan.

Everything but the exterior walls and the roof structure came out. The kitchen and the main living space were combined, the single bathroom upstairs became two, and the whole house got new mechanical, electrical and plumbing.
Two structural walls came out for the open plan, which meant a beam and a pair of point loads carried down to new footings.