There is an unfortunate tendency for people to think of interior design as a binary proposition: there are fixed elements (structure, furniture and fixtures) and there are flexible elements (furnishings) which are small, light, additive and non-essential.
Designs like these, however, can teach children from an early age that the line between permanent and portable is not so cut and dried as it may seem as illustrated by the GAB children's furniture design company.
Rolling bed units over comfortable child-sized couches, for example, allow kids to maximize play, work and relaxation space during the day but shift their interior space to sleep at night.
Movable tables and beds on wheels make it possible for each child sharing a room to customize the space when they are using it and to open up more room during the day by tucking one bed beneath the other, adding fun and functional to a simple small space design.
Still other designs shift to accomodate additional storage space or custom configurations of shelving, beds and otherwise conventionally fixed-in-place design elements.