User blog comment:GrandMethuselah67/Lore Sheet: The People's Imperium of Neohumanity/@comment-4867780-20150810003841/@comment-26322734-20150810164117

Well, think of it as an assembly line. Except extremely small and more than billions of things are going on at once. But don't get me wrong; the process of building superstructures doesn't take seconds, and not just anybody can do it. Ozmand Brains are actually now responsible for mapping superstructures. Also consider that the U.R.H. has beings like MAGNUMOPUS on their side now, who has abilities such as Data Warping and Codification/Decodification (and, as a result, "magic", or what passes for it in my 'verse).

Energy isn't a problem. Even when the U.R.H. didn't have control of the Milky Way, they had several stars, most larger than our own sun, under their control via metro spheres. Our sun alone generates " some 386 yottajoules per second" to quote its entry on this sheet. In comparison, as of 2008, we used 142.3 kilowatts per hour -- that's only 39% of the planet's total energy. But that's of 2008, though it probably hasn't changed much since we're not quite yet Type 1 on the Kardshev Scale. In practice, mining quantum voids is actually pretty inexpensive; as I said, the energy required to remove quark-gluon particles is the exact amount of energy to create one. With all of this being said, quantum voids are just one of many methods they use to get actual matter, not even their main method. The sheer amount of stuff in the galaxy is much more than extremely large. Their engineering process is simply taking that stuff and condensing it into superstructures and modifying as possible; which is the same process that Kazzack used to greate his megacity.