Small woodwork project

I am looking to have a piece of furniture built. I am looking for a chair to accommodate a teenager / young adult with special needs. Essentially, I simply need a larger sized version of a normal wooden highchair. I am open to any sort of design but would ideally like something that can either be disassembled easily when not in use, or folded away. No painting or finishing required, merely the woodwork. The attached image is simply a guideline to illustrate roughly what I'm after and need not be viewed as strict plans.