First, the timber from the trees that the Undead titans had cut down was gathered and lined up.

「【Wither.】Get up. Cut. Get out.」(Vandalieu)

Vandalieu used the death-attribute magic spell【Wither】to remove some water from the trees and have them dry up, turned them into Wood Golems, used【Golem Transmutation】to have them cut themselves into appropriate sizes and then removed the souls possessing the wood again.

With this method, the Devil’s Nest’s trees turned quickly into usable timber. And then the Ghouls built partitions between rooms and furniture. The Ghouls were originally native to a Devil’s Nest forest; since they  didn’t need particularly elaborate furniture, this work was finished in several days.