This abbey is thought to have had a refuge in Diest since the early 15th century. A year later, Abbot Van der Schaeft commissioned major new works, involving the construction of a small chapel and a new residential wing. The entire complex is built in brick with mullioned sandstone windows. The plinth is predominantly red sandstone.
The gatehouse is decorated with a late gothis sandstone tabernacle or niche. The stepped gable beyond the gatehouse has six steps and a top piece. The gable is divided by two horizontal mouldings, one at the level of the lower sills of the second floor windows and the other above the higher central window. The ends of the latter rail run on to form the coping stone of the first steps in the gable.