To ensure an accurate installation, all door opening measurements must be taken from the specific side of the wall where the door coil will be located. Before you begin measuring, it is important to check the floor condition for levelness and evenness and record your findings. You should also identify and record the jamb type while observing the jamb quality for strength, plumbness, and any signs of twisting or unevenness.

When taking the dimensions of the opening itself, always measure the width and height at their greatest distances to ensure proper clearance. To complete the measurement process, record the dimensions for the left and right siderooms, as well as the vertical headroom and horizontal backroom. These steps will ensure that the door has adequate space for both housing and operation.