Course, to satisfy the OP's problem, why can't you build a temporary dirt or stone ramp, or even temporarily attach stairs to the side of the wall? Scaffolding sounds like a lot more trouble than it's worth.
While that would work, scaffolding appeals to me more. Firstly, a re-usable construction aid is not as wasteful of resources as making (and later destroying) some temporary structure to climb on, and secondly as it has a more realistic look. (ie, looking at some ongoing construction you might say "this building is being worked on" rather than "why would anyone build stairs out there?")