You can display the zone volumes in 3D view as follows.
Example: Display 1st floor zone structure
1. Switch ON the Transparency with wireframe option
2. Build 3D model in Custom mode selecting the 1st floor only.
3. Select - View - Build 3D - Space volume computation
Select Show zone volumes
Specify zone group colors
Select View - Visual styles - Consistent color
You will get a result similar to the figure below: