Municipality seeks building/room scheduling software

We are a community in southern Germany and are looking for a building or room scheduling program for various event spaces, a sports hall (which can be used for multiple purposes), restroom trailers, and a dishwashing trailer.

The following requirements should be met:

• Building/room scheduling (including individual sub-rooms)
• Calendar view
• Conflict management
• Seasonal planning function
• Possibly an accounting system
• Windows-compatible
• Web-based is possible

We anticipate 2–3 software workstations.