A small space idea, like a tree house in your room. Utilize all space with shelf stairs up to the bed box. Get a closet too and all of it up off the floor space. Great for a boys room. Put a BB Net on the bed and voila! they can play indoors.
Building Stairs: Start with the big boxes. In this example, we have a large opening for a washer/dryer combo unit. For any opening larger than double the plywood with glue and screws to provide adequate support for the stairs.