Estimate the busiest practical scenario
For a project, identify the largest overlapping crew and working hours. For an event, describe attendance, duration and concentrated breaks. Include support staff. Count existing bathrooms only when the same users can access them during the relevant period.
Check more than the total
Separated activity zones, accessible entry, washing and service all influence the arrangement. Discuss where units would sit as well as how many are proposed. Have the responsible employer or organiser confirm applicable requirements; a universal online ratio cannot resolve the details of every site or gathering.
Tell the provider what could change
If attendance or trade schedules are unsettled, describe the likely peak and the uncertainty. Ask what assumptions sit behind the proposed quantity and what change should trigger a review. Confirm whether permanent bathrooms remain available throughout the relevant period. Keep washing, accessibility and distribution in the same discussion as the cabin count.
- Peak use and uncertain assumptions
- Availability of existing bathrooms
- Changes requiring a revised proposal