A bunk bed is a type of bed configuration wherein one bed is stacked or placed over another. The bunk bed design is most commonly used to create two functional beds; however, it is possible for three beds to occupy a single floor space when it is properly reinforced and secured in place. There are also unconventional bunk beds where at least one of the multiple beds is attached perpendicularly in an L-shape instead of just being stacked flush on top of another. Some bunk beds even have a third bed called a trundle bed hidden inside a drawer underneath the bottom. Instead of a trundle bed, other bunk beds may have a set of drawers for clothes. Even though there are slight variations in the aesthetic features incorporated, the basic structural design remains unchanged.
The size of a Standard, Single, or Twin bunk bed is 75 in. x 39 in. x 65 in. The size of a Full bunk bed or Double bunk bed is 75 in. x 54 in. x 65 in. Other sizes of bunk beds also exist such as short bunk beds, triple bunk beds, and bunk beds with trundles. Queen and King bunk beds are rare.