[Interior of the church at Fontenay, facing west, built early 12th century, photographed by Jean-Christophe Benoist, source: Wikimedia Commons]
[Ideal plan of a Cistercian monastery, Carla Christiana Carvalho, source: Wikimedia Commons]
The chronicler Odericus Vitalis tells us that Cistercian monks built their monasteries with their own hands. He almost certainly did not mean that they let unskilled monks build in stone. Rather, they almost certainly put up preliminary wooden buildings themselves and assisted in the actual construction of the stone buildings, but the skilled labor would have been done by professional masons hired from outside. The Order did have a few experts in building within its ranks, and with them acting as advisors alongside the abbot, Cistercian architecture maintained its simplistic, practical bent.
*The presbytery is the area around the altar and the space to the east of it (in a traditional church). If the walls at the end are rounded rather than squared off, the resulting semi-circular space is known as an apse. For an overview of spaces in a monastery, try here.
**Though hopefully in colder climates the cloister walk was enclosed from the garth (the open space in the middle). Asceticism does not mean freezing to death.
Cook, William R. and Ronald B. Herzman. The Medieval Worldview: an Introduction. New York: Oxford University Press, 2004.
Stalley, Roger. Early Medieval Architecture. Oxford: Oxford University Press, 1999.
Cistercian Architecture - Wikipedia