While playing through Saloon Tycoon for the first time, we weren't able to figure out whether the roof counts as a floor or not. There are two possibilities:
1. The Roof is a Floor
In which case the tallest section would be:
Floor 3: Roof
Floor 2: Another room
Floor 1: Saloon
This is how we played it, since the roof is a tile just like any other it seemed like it should follow the same rules. This led to problems with the Luxury Suite, which is required to be on the third floor.
2. The Roof is not a Floor
In which case the tallest section could be:
Floor 4. Roof
Floor 3. Another room
Floor 2. Another room
Floor 1. Saloon
This helps the Luxury Suite make sense, but it causes a conflict because the roof is now different than other tiles. It essentially becomes a fourth "floor".