There is a german word "Instandbesetzung" which translates to "maintenance squatting" or "restorative occupation". The first part is german "Instand-setzung" an

There is a german word "Instandbesetzung" which translates to "maintenance squatting" or "restorative occupation". The first part is german "Instand-setzung" and the second "Be-setzung" so "Instand-be-setzung". The basic idea is that a property deteriorates if not occupied, so when these squatters take over an abandoned property they improve it. The reality of german punk culture often did not follow this ideal: in the worst case it was a sham used by junkies to give an aura of legitimacy to their occupation, in the best case chaotic good punks had a different idea of what "maintained" means compared to more orderly people. The concept also exists in informal settlements unrelated to punk culture: to loosly quote a women living in the Venezuelan Tower of David, a precariat slum: "everything we did here was to live like decent people" and yet it still was a shanty town in an unfinished abandoned office tower. The people living there managed basic utilities for their community, which is impressive, but calling the tower maintained would be farfetched. Cyberpunk author William Gibson features this concept quite often in his slum ridden dystopia, but it is most prominent at the end of the short story "Red Star, Winter Orbit" which he wrote together with Bruce Sterling. The german translation uses the above mentioned word, but in the english original they describe themselves as "Squatters, I guess you could say." so i don't think there is an english word for this concept, neither for buildings, nor networks.