Sliding glass doors are practical for creating a large doorway. This eliminates the need to cram a heavy piece of furniture through a narrow opening when moving from one room to another. With an external screen installed on one side of the door, natural wind flowing through the wide opening can also help reduce your air conditioning costs and repel unwanted bugs and insects. With glass sliding doors, you are able to save space because they don’t swing in and out. The door moves in the same line as the top and bottom slide mechanism. The slide track on a door rail makes perfect sense for homes with minimal space.