Timber infill
If there are high door openings in a building, the upper area can be closed by a mounted timber infill. In this way the door leaf is not as heavy for very high elements and can be opened and closed more easily.
The timber infill has the same surface as the door leaf, so that a uniform appearance from the floor to the headpiece of the frame is given. A horizontal transom bar between the door leaf and the timber infill is not necessary.