The ornamental design for a holder for buildingpanels, as shown and described.
1. Holder for building panels
1.1 : Perspective
1.2 : Perspective
1.3 : Perspective
1.4 : Front
The design concerns a holder for building panels; reproduction 1.1 is a perspective view; reproduction 1.2 is a perspective view of a part on the right side; reproduction 1.3 is a perspective view of a part on the left side; reproduction 1.4 is a front view; the building panels in dotted lines are only for illustrative purposes and form no part of the claimed design.