Ask the venue what stays open
Confirm which permanent toilets are available to guests and staff during preparation, the ceremony, reception and breakdown. Do not count facilities that are inside a closed building or reserved for another booking. Ask whether temporary equipment is allowed and who approves its position.
Compare the experience with the site limits
An upgraded cabin may fit a smaller installation; a restroom trailer may provide different conveniences but require more access and utilities. Identify the features that matter and have the provider describe the offered model. Include accessible options in the first discussion rather than trying to add them to a finished layout.
Trace the route in event conditions
Consider how people will find the facilities after dark or while catering vehicles are moving. Keep the approach away from food preparation and decorative obstacles. Discuss surface conditions and weather contingencies with the venue, without assuming temporary equipment can be relocated during the event.
Give each supplier the same schedule
Share the setup window, guest arrival, event end and permitted collection period. Identify who can approve a change if the planner is occupied elsewhere. Ask about supplies, service and whom to call if something needs attention; confirm those arrangements in the proposal before booking.