Researchers in China are working to help us live even more efficiently in smaller spaces. They have developed an algorithm specifically designed to see if designs are foldable and if so, they help to arrange the puzzle pieces for 3D printing, using a hinge design, as well as other features they are still working on. The equations may work well for furniture but the algorithm can also work for other 3D designs and structures that can then be 3D printed. They are also trying to incorporate features like foldable shelves, as well as attempting to 3D print the furniture in one piece, already folded. More information on this research being done by the Chinese can be found here: http://3dprint.com/69784/3d-printed-furniture-foldable
Below is a diagram showing just how this 3D printable furniture can fold up:


And another image of an actual chair they created from a 3D printer: