The Building section of the Metrics sidebar shows:

The gross floor is shown as a percentage of max buildable area beside the Building section header.

Function areas are shown in sqft or sqm - to view the area as a percentage, hover on the corresponding section of the bar chart in the Building section.

Building functions are assigned to extrusions and used to calculate gross floor area.

To create a building function:

To rename a building function click on the name, enter the new name, and press Enter to confirm the change.

Extrusions assigned a site function will be shown in the building function color when viewing the Function style. To change a building function color, click on the color square beside the building function name and select a new color from the picker.

To delete a building function, click the - button that is shown beside the function name in the Building Parameters menu. Note that any elements with that building function assigned will automatically have the function unassigned as a result.

Setting a max FAR will add a constraint to your site - if your building(s) exceed the max FAR, the FAR field will turn red to warn you that the constraint has not been met.

To set a max FAR, open the Building Parameters menu and enter a value in the Max FAR field. Note that a site boundary must exist for constraints to work.