Explain the pattern of attendance
A total visitor estimate can hide very different demand. People arriving in one group, passing through gradually or working overlapping shifts do not use facilities in the same way. Tell us when the largest group is present and how long they stay.
Meals, breaks and programme intervals can concentrate use. Include those moments in the brief. For a worksite, identify the actual daily workforce rather than every person who may visit during the project.
Account for other facilities honestly
Only count permanent toilets if they are accessible to the same users during the relevant hours. A locked building or a distant restroom may not provide dependable relief. Explain any limitations instead of simply subtracting a bathroom from the temporary requirement.
Accessible facilities and handwashing need their own review. A total cabin count does not establish that the arrangement is suitable for every user or meets every applicable requirement.
Review the estimate when plans change
Share your best information even if attendance is uncertain. Identify likely increases and ask how changes can be handled. Equipment availability and service capacity should not be assumed to expand instantly on the day.
We avoid a universal numerical ratio because it can conceal important differences in use, duration and site needs. Discuss the proposed arrangement with the rental team and confirm any regulatory requirements with the responsible organiser or authority.