Start with the event outcome, not the room. A leadership workshop needs privacy and reliable presentation technology; a product launch needs a strong arrival sequence, production access and brand flexibility; a client celebration may benefit more from harbour views and memorable hospitality.
Next, map the full guest journey. Check public transport, parking, coach access, accommodation, accessibility, loading times and the route from registration to the main room. In Sydney, also test peak-hour travel assumptions and build a wet-weather plan for rooftops, terraces and marine venues.
Published capacities are a starting point. Ask for the capacity in your preferred layout after allowing for staging, AV, catering stations and circulation space. Always confirm current inclusions and restrictions directly with the venue before contracting.