Abstract: A wall having an interior channel extending vertically along one and preferably both end edges thereof. This interior channel is closed by an openable door arrangement which can be hingedly moved into an open position so as to uncover one side of the channel and permit cables to be laid directly therein. The door arrangement is externally covered by a portion of the flexible side mat which extends over the entirety of the panel side, including the door, so as to permit the portion thereof over the door to hinge outwardly when the door is opened so that removal of the side mat is not required. The side mat is formed as a continuous covering so as to avoid undesired seam or joint lines.