Zones are 2d areas that allow you to quickly map out and measure different Usages across your site in the early stages of your design.
Zones can also be used for specific parts of a project, for example, car parking areas.
To create a Zone, sketch the proposed outline of the Zone
Once you have the outline in place, make sure you are on the Zone Tool:
And then use your finger to tap inside the enclosed shape.
A Zone will be created based on the current default settings.
With the Usage Palette open you can also drag a specific Usage Type, and drop it within the enclosed shape. Again, a Zone is created based on the current Default Settings along with setting the Zone Usage based on the Usage Type that you dragged.