The Occupancy % (v3) calculator computes the percent occupied using the number of units in a building that have been rented out as compared to the total number of units in the building minus the rooms that are out of order (OOO).
Resource:
Dopson, Lea R., and David K. Hayes. Managerial Accounting for the Hospitality Industry. Hoboken, NJ: Wiley, 2009. Print.