Built-in book cases can take any space from drab to fab. Unfortunately, these custom-built units are often expensive—and if you don’t own your home, not worth the investment. Now thanks to the Japanese design firm Nendo, and their new shelving unit called Nest, you can have a set of book cases adjusted exactly for your living space. This ingenious shelf stretches to accommodate any size. Each unit is made from carbon fiber materials, so it will hold up under extremely large amounts of weight. Plus, unlike built-ins, when it’s time to move, you can take these customizable pieces with you to adorn your new home.