Placement of furniture in children's rooms

The services of a children’s room interior designer are required. It is necessary to arrange the furniture. We build children's rooms for boys 14 and 7 years old in the attic. I can't think of a way to arrange the furniture.
I want something interesting and modern. Maybe custom furniture.

Children will be finished with a tree (Eurorace). Laminate floor. In the middle of both rooms are two load-bearing pillars, which divide the rooms in half.