Yeah, but those things are always in flux, made of many individual parts that may often been seen in isolation (I don't think many people except for city planer

Yeah, but those things are always in flux, made of many individual parts that may often been seen in isolation (I don't think many people except for city planers know which particular "project" a given set of roads belongs to), and have no definitive "completion". For the space station for example, I'd consider it "completed" the moment it was taken into operation, the rest is building upon it and maintaining. Cathedrals are single objects, though of course I don't know how they were built, and for how many hundred years they may have seemed "complete enough" to the untrained eye.