When purchasing a sliding glass door, there are a few factors to consider that should be at the top of your list. You should look for an energy-efficient door first. The sliding glass doors that are currently available on the market can combine your interior and exterior spaces without compromising energy performance thanks to features like warm spacer systems, Low-E glazed glass, and gas between the panes. Last but not least, check that your sliding glass doors will look good with your house and be simple to operate and clean.