Maybe wall sections with built in services could work too. e.g., a wall with plumbing to handle a bathroom on one side and laundry on the other. Design a house

Maybe wall sections with built in services could work too. e.g., a wall with plumbing to handle a bathroom on one side and laundry on the other. Design a house around these service walls in strategic locations, then fill in the other, more-standard plasterboard walls. If the more technical bits (electrical, plumbing, etc) could be done by accredited tradesman in the factory, leaving a general worker to screw on taps and plug in power cables, that might reduce the individuals required on site during the assembly process. The factory professionals could knock out dozens of custom service walls (even if each was slightly different) in a day, versus driving around to individual building sites in the traditional model.