 In the 12th and 13th centuries, Cistercian barns consisted of a stone exterior, divided into nave and aisles either by wooden posts or by stone piers.The Cistercians acquired a reputation in the difficult task of administering the building sites for abbeys and cathedrals.St Bernard's own brother, Achard, is known to have supervised the construction of many abbeys, such as Himmerod Abbey in the Rhineland.