# Creating Floor Levels We automatically create levels by the bottom most point of every mass, then assigns each mass to its corresponding level. But for us to create and assign levels that best represents your model, there are a few points you should know: ## Ground Floor is always at Elevation 0.0 You must position your model so that the ground floor objects are at elevation 0.0. This is how we determine which levels are above ground and which are below.

## Levels are place at floors We infer levels from the floor of your objects. So only where there are floors, there are levels. Your model may have objects with different heights, such as auditoriums, or may even have outdoor spaces on some levels. We will still correctly create levels.

However if your model has an empty space without any objects, we ignore that space and place levels on the next floor we can find.

## Skip floors are possible We generally group objects by their elevation, and allow some deviation. So if your model has objects that belong on the same level but have different elevations, we may still correctly set their levels.

The acceptable elevation difference for skip floors depends on your model, such as the average height of objects and number of levels. But we recommend you keep the difference around **1 meter(3 feet)** for your objects to be considered on the same level.