For garage applications, the conventional overhead garage door gives you the full width and most of the height of your garage door opening but interferes with the interior space above the door. Double sliding doors don't interfere with the interior space, but you can only open half of your garage door opening. Roll-up doors are expensive and besides that, they just don't look "Barny". Our unique track-and-trolley double bi-fold system eliminates overhead interference and occupies mere inches of side space when fully opened to their standard 18' width. The plans show the doors folding in to open as demonstrated in this video (click for video), but can be easily modified to fold out by simply reversing the plans. Our friend and barn builder, John Cowdrey in Broken Arrow, OK demonstrates in this other video (click for video) how he did his. John got creative and designed this exterior version of the track on his own! Either way they work great!