Sliding glass doors have lower glass-to-frame ratios which provide more insulation from the scorching summer heat. Transparent sliding doors also allow natural light to pass so there is no need to consume electricity during the day. 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.