Luke talked to the man in the suit who was in charge of construction and obtained the right to use five makeshift units.
There wasn't anything for the man to be unhappy about.
For this big business, he had brought enough materials and manpower with him, and had also brought the materials to set up some makeshift operation units as was standard practice.
But when he got the blueprint, he realized that it was a super simple job. It couldn't even be considered an engineering project, and would be completed by nightfall.
As was his habit, however, he still set up some operation units. At the very least, everyone needed a place to drink water and rest for a while.
Apart from one unit which was used as an office, he wasn't using the rest.
If the big boss who was paying him wanted to use them, so be it. In any case, it didn't make a difference.