A useful distinction
A room that might be available and a confirmed booking belong to different categories. The same distinction applies to equipment, funds and volunteer time. Combining them in one confident resource total can make an uncertain plan appear ready.
Put it into practice
Use columns for confirmed, proposed and unavailable resources. Add the relevant date and decision owner. Update the list when an agreement changes, and keep private contact details separate from the public summary. This is a planning record rather than a promise that every resource will be obtained.