You could build the external structure and a "floor" (steel plate) for each level, then you could swap out trailers if needed, a vertical trailer park. Would n

You could build the external structure and a "floor" (steel plate) for each level, then you could swap out trailers if needed, a vertical trailer park. Would need some way to get up and down and toilet/water. Tbh by the time you've done all that you might as well just build a normal modular high rise (that's how the local budget hotel did it, nearly whole thing turned up as a series of containers each prefitted with plumbing and power, then stacked together, hooked up and done, it went up insanely fast).