Transients vs. Retail?

Students using a dining hall would be considered "transients". You just need to estimate the number of total of "student hours" the hall is used and then divide by 8 hours per day to determine the FTE. So for example, 100 students spending an average of 2 hrs/day in the hall would come out to 25 FTE's

It makes a difference as to how the water usage is calculated.
Per the Reference Guide (p171) "Most buildings with students, visitors, and retail customers will also have FTE occupants. Half of all students and visitors are assumed to use a flush fixture and a lavatory faucet in the building and are not expected to use a shower or kitchen sink. A fifth of retail customers are assumed to use a flush and a flow fixture in the building and no shower or kitchen sink."

Because there is more than one way to view something? Personally, I would not have used Charles' method although I do see it as valid. The transient population is variable and their behavior changes throughout the day. The form is allowing you to customize. For example, your students may not make use of the facilities at dinner because they've been to their dorms before hand but they may use them during lunch. If your lunch population is less than your dinner population, then you can adjust the water use in the form instead of making sweeping assumptions that may not be applicable to the individual project.

For the record, I would not have done things the way Charles does not because I feel he is wrong but because our projects have transients that have more predictable behavior which allows us to model more accurately. His way is completely valid.