The first raised sleeping platform, a type of loft bed, was used in ancient Egypt. Beds evolved over time and the standard one-piece bunk bed became common on ships. These bunk beds were a single wooden or metal frame that supported two mattresses. This type of bunk bed gave way to stacked bunk bed when demand for home use rose. Single-framed units are inconvenient to move and install in the home, but stacked beds are more versatile. Bunk beds are still the standard sleeping arrangement in ships, submarines and other vehicles such as RVs, and bunk beds are a common sight in many home bedrooms.
A bunk bed is two or more beds stacked on top of each other to create sleeping areas. Bunk beds include ladders or stairs to access the top bunks, and some models include decorative features such as slides, tents and flags. Twin- and full-mattress sizes are available, as well as custom sizes, but bunk beds are rarely larger than full-size.
The traditional bunk bed is a twin bed stacked on a second twin bed. An L-shaped bunk bed is a bottom bunk that is turned out 90-degrees from the direction of the top bunk. L-shaped bunk beds may be twin, full or a combination of twin and full-sized beds. The loft bed is a variation of the bunk bed that excludes the bottom bunk. Instead of a second bed, the loft bed has open floor space.
The space-saving feature of the bunk bed is possibly the main draw, but the bunk bed has additional benefits. A bunk bed is an imaginative play space for children, and specialty-themed beds offer features such as tents and slides to heighten play. Loft-style bunk beds provide storage space, increase floor space and offer hide-away areas for play.