["Codex Sangallensis," 9th century, Source: Wikimedia Commons]
[19th century drawing of the Plan of St. Gall, Source: Wikimedia Commons]
While the Plan shows what one could call the “average” Benedictine monastery layout, it doesn’t actually correspond to anything that has actually been built. Scholars are still debating the original purpose behind its production, along with most other things about it, but there are things that can be learned from it. At the absolute minimum, it provides an excellent example and teaching tool for learning the layout of a Benedictine monastery.
Though the scale is not necessarily* consistent, the Plan shows all of the buildings that a decently sized monastery would need in order to be relatively self-sufficient, from an infirmary to pens for livestock to guest quarters. Most architectural drawings only show the church and the buildings immediately surrounding the cloister, which means that people don’t generally think about what else a monastery would need.
Though I call this the “average” plan, it’s worth keeping in mind that this wasn’t always the model, particularly in the time when this was drawn. It was around this time period that Charlemagne decided that monks and nuns in his lands should live by the Rule of St. Benedict and no other. This particular type of plan became attached to that and it spread from there.
*This is one of those things they’re still debating. It comes with the territory. Yay.