How to Choose a Bunk bed With Double Underneath Bed Frame double bunk bed with desk underneath beds typically appear utilitarian, but this sleek design is a departure from the norm. It also converts into two separate twin pieces as kids outgrow it. It's also a good choice for safety with full-length guardrails and a ladder that can be hung on either side of the bed. The ladder that is angled is more comfortable to climb than straight ones, but takes up more space. Size If you are trying to maximize the space in your child's bedroom or guest room, a double bunk bed with space underneath bed is a good choice. Typically, they are made up of two beds placed over the other, they save both floor and closet space. There are many types of bunk beds and you can pick the one that is best for your space. The most popular designs include twin beds, triple bunks, and full-size bunks. The size of a bed frame determines the maximum mattress size that can be accommodated.