Space required for Automatic Sliding Gates
Single panel sliding gates or rolling gates as they are also know must have enough room to open:
The Automatic Operator is normally off the side of the driveway so when the gate is closed the bottom rail must extend far enough to reach the operator, which is part of the reason for the extra 400mm. Also the gate needs to overlap the posts by at least 100mm, which looks nicer.
A gate may slide to the left or right:
If you don't have enough space for a single panel sliding gate then there is the option of a two panel sliding gate either Bi-Parting (sliding apart from each other) or Telescopic (one sliding in front of the other).