Well, regarding plumbing, running water should definitely be do-able, from a survivor’s standpoint.
I mean, start with a well, connected to a pump, connected to a large tank on the roof.
Use the pump to send water upwards, then build a pipe system to distribute this water as required.
But:
- Existing pipe system would need to be overhauled (eg. connect to your new pipe system.
- Water availability would be dependent on the tank - you’d have to regularly refill it (though, a water level sensor + power switch hooked to start/stop the pump could automate this i guess)
This is well within the capability of a good engineer. Pipes do not have to run inside the walls, they can be external too.
Still, from a game mechanics perspective, i cannot see an added value to limited piping systems (other than role-playing): A few standing tanks should suffice for all your related needs. Also IIRC the implementation of large connected grids within non-vehicle structures is a big hassle game engine-wise. So why bother?