Storage containers are built to specific standard measurements. This means that, although the height and length can vary, all shipping containers have same width. This makes it easy for shipping containers to be modified and combined into larger structures. The common structural design simplifies any further design, planning and transport. Transportation is also easy with shipping containers, especially considering it's the basis of their design. Because of the containers' modular design, additional construction is as easy as stacking and combining more containers. When empty, they can be stacked up to 12 units high.