At the Southern side of the schoolmaster's house excavations brought about the remains of a 20 meters long and 7 meters wide stone building. The top of the walls were covered by a burn layer, and tzhe time of the fire can be dated to about 1230. The building was probably built and used in the beginning of the 12th century.

The excavating archaeologist discovered three ovens and glass-like remains. The laboratory examinations confirmed that workshop was used for glass manufacturing by the benedictine monks. The workshop was also uswed by the cistertian monks until it was burnt down in 1230.