In building you can use your own or a factions RM pile if they give you the privs to use them. But you would not be able to use them if they are someone else's as in another players. I guess in all you cannot use other players RMs anywhere but you can use someone elses faction RMs if you have the right privs
Not 100% clear but I'd heard something about being able to use other owner's RMs if you kicked off production in said owner's factories/shipyards. With your own privs applied (manager etc).
The rules doesn't exactly say no in this aspect.
“The materials must be (1) in the facility/station doing the producing or (2) in facilities/stations that are (a) loadable facilities in the city* (See Mining: Storing Materials) or an adjacent space station and (b) are operated by the producing facility/station operator, or the person starting production, or are managed by the producing facility/station manager, or are owned by the producing facility/station owner. ”