As gunpowder weapons became more common, the castle was expanded and rebuilt as a fortress. On the top of the hill, in the direction of Weiler, a bulwark was built to protect the castle. The old keep was rebuilt with extensive walls. Additionally, the terraces below the castle were expanded and fortified. The castle was used for the Ulm representative or Vogt and the western section of the castle was rebuilt as proper home for a patrician Vogt.