It also can be used to create some extra space, by giving you a wall storage area in a space that could previously be used only for the door. It's ideal for bedroom or office closets, kitchen pantries, laundry rooms, or just about any other closet or storage area in the house.

Like a bi-fold door, Space X Doors are constructed in two or more units, hinged together in the middle and operating on an overhead roller and track assembly. Since the bookcase extends out from the wall, the track is actually contained within an overhead cornice assembly that resembles a cap over the top of the bookcase. Close tolerances between the sections of the bookcase and also between the case and the overhead cornice help to conceal the hinges and the roller assembly.

Like any other quality bookcase, the Space X has adjustable shelves and is capable of holding more than 300 pounds of books and display items. Its operating mechanism is designed in such a way that opening the bookcase will not disturb any of the objects on it – just slide it open, and nothing falls off.

SIZES AND OPTIONS

Space X Doors can accommodate any opening from as small as 24 inches wide to as large as 10 feet. Standard sizes are 49 inches wide by 83 inches tall for openings from 24 to 46 inches in width; 61 inches by 83 inches for openings up to 58 inches wide; and 76 inches by 83 inches for openings up to 73 inches. For wider openings up to 10 feet, multiple panels are used together.

There are three styles of bookcase available, as well as a number of material options. The Traditional Series has sides of medium-density fiberboard (MDF) with wood-veneered banding on the front edge and no stile. The Classic Series has a 3-inch-wide veneered MDF front stile, which gives the bookcase a little wider, more substantial appearance in front, and the Masterpiece Series steps up further to fluted stiles of solid hardwood, and shelves with molded hardwood front edges.

Material and color choices include oak, maple and cherry – unfinished, or in several stain colors – as well as white and almond melamine and paint-grade MDF. There are also other woods available as a custom order.

To order one of these units, you'll need to have several pieces of information available. You need to know the height and width of the opening you wish to cover, including trim; the amount of clearance between each side of the opening and the adjacent walls; the ceiling height; what type of subfloor and floor covering you have; and whether you want the doors to pivot on the left or on the right.

Space X Doors should be available by special order from some door companies, or you get an estimate and place an order off the Web at www.spacexdoors.com.