The rough plan for the building of the future .. taadaa
There is two major scales, mod system facility and mod system home.
Facility consistists of a metal framed one story building using https://en.wikipedia.org/wiki/Space_frame that is 3-5 meters in height, the subfloor would likely be concrete or asphault with anhor bolts and the flooring would be hardwood, granite, or other industrial flooring such as:
Various subfloor treatments:
http://www.florock.net/industrial-flooring-project-gallery/ http://www.rubberflooringinc.com/ https://usa.sika.com/en/flooring/flooring.html
Interlocking flooring systems:
http://www.eventdeck.com/HexaDeck.shtml
The facility would not provide more functionality wise, the interior portions would be using the mod system home parts and the roofing is currently TBD other than roof gardening (green roof) and solar being a big part.
As far as wall and ceiling aesthetics in the facility scale they would be left exposed to be covered by mountable mod system home walls and ceilings. The facility would provide power and water and sewer hookups at predictable places with predictable proportions between them.
The home system would consist of various kinds of walls in the size range of 1mx1m to 2mx4m, all sizes could connect, but not all configurations of all sizes would be compatible, to be very frank and speak to anyone who is trying already to do something like this project in the not first world, it should be inherently imposible to configure a situation where you shit where you eat. Sensors, power, lighting, mounts, would be built in. Insulation would also be configurable allowing for weather and sound proofing, in such cases the walls maybe thicker.
In both the facility and home system the exterior aesthetic should be highly up to choice, a haunted house, a greek temple, a spaceship. The majority of this project is about the engineering and usability aspects of the system, and then to enable attachment of any kind of aesthetic facade.