We’ve been building houses, apartments, townhouses, terraces, and other residential buildings for a long time.
But, almost universally the majority of the construction work is done by hand and on the site where the dwelling will be used although:
building materials are either made at their source [timber, stone, etc] and/or processed or manufactured in factories and delivered to site for use or installation, and
equipment and appliances [ovens, stoves, HVAC, kitchens, etc] are manufacture elsewhere and simply installed.
So, why don’t we manufacture more of our dwellings in factories on production lines for delivery and installation on site [and possible future removal and relocation]? That process has worked pretty well for all kinds of small and large products over the last 100 years.
This interesting @NYT article discusses the history of factory made or modular housing in the USA suggesting that less than 2& of a new single family homes are built in factories, that the time taken to build a house [an average of 8.3 months] is longer now than 50 years ago, and that construction costs account for more than 60% of the price of housing. All of which would be reduced by factory processes.
Plus, there are fairly obvious benefits to quality control and assurance, waste management, weather delays, safety and working conditions, an automation.
So, how do we stack these modular homes on top of each other?