To prevent children and guests from walking into closed doors, stick on two rows of transfers about 3 ft / 1 m above the floor.
To stop birds from flying into the glass, hang chimes outside the door.
To insulate glass doors, buy a roll of special reflective film. This is applied wet, and squeegeed into position, where it forms a perfectly clear but reflective surface. It also acts as a safety measure, further increasing the impact resistance of the glass.
Add security to the door by fitting a special sliding door bolt to each frame. This will prevent the door from being moved or lifted from its frame.
