IndoorAtlas SDK reports the floorPlanId and floorNumber when the user enters a floor. When fingerprinting, the data from all the floor plans of the same floorNumber is consolidated across venues to create a smooth experience when walking between nearby venues. Due to this, it's important that the floorNumbers of floors in nearby venues are consistent with respect to each other. 

Some venues have several buildings, each with different ground floor level (measured from the sea level, compared to each other). To best match the floorNumbers across buildings in such cases, follow these instructions:

• Add just one "venue" in IndoorAtlas
• Take the building with the lowest ground floor (measured from sea level, or any reference) and 
  • Set the ground floor floorNumber 0 
  • Set all other floors of the building accordingly, numbered up and down from 0
• Take the next building(s)
  • Examine from the physical environment, from cad files, or from any other source, which floor's level in the building best matches with floor 0 of the first building ("e.g. from Building A's floor 1 you see the windows of floor 0 in building B")
  • Set that floor's floorNumber 0 and the rest of the floors accordingly

Remember also to set the floor height accurately (the floor height is the distance from the floor in question to the ground floor). This further improves smooth transitions between floors.