While I doubt that either Death Star required aluminum siding or roofers, Randal has a fair point in Clerks. While Imperial Stormtroopers are enlisted from all across the galaxy, many of them would come from backgrounds which did not include construction.
Is there any evidence (C-Canon or up) of just who built the Death Star?
From the Clerks script:
A construction job of that magnitude would require a helluva lot more manpower than the Imperial army had to offer. I'll bet there were independent contractors working on that thing: plumbers, aluminum siders, roofers.
Not just Imperials, is what you're getting at.
Exactly. In order to get it built quickly and quietly they'd hire anybody who could do the job. Do you think the average storm trooper knows how to install a toilet main? All they know is killing and white uniforms.