Ive seen my dad's commercial building get constructed, its not as easy as Just pouring cement , they need to dig a trench 5 feet deep inside the frame work , most likely every corner then a long trench connecting every corner and the trench straight down the middle connecting the dots together then place beams for strong support and then pour cement , but before that plumbing for the bathroom if there is going to be one .
Then after the cement dries they start constructing the metal walls , once that's done then electricians , and plumbers and ac , finish running there lines in the building etc ..
It's not that easy lol