GBA = Gross Building Area - The total area of a building
GFA = Gross Floor Area - The total area of a building minus core, corridor, and any specified area types (eg. mechanical room)
NSA = Net Sellable Area - Some percentage of GFA meant to account for wall, floor, ceiling, and structural element thickness.
By default GBA will be selected in the Building section in the right sidebar, and you will see a breakdown of building function GBA areas. Total GFA and total NSA are shown below the breakdown section.
Changing area breakdown type
To change which breakdown is shown, click the toggle button in the top right corner of the Building section.
Excluding areas from GFA
To exclude area types from the GFA calculation, go to the Area Types tab in the Metrics Settings menu and set the area type to No in the Include in GFA? column of the table.
Note that if you are in Calculated units mode Efficiency is used to calculate the GFA rather than the Include in GFA? setting.
Setting the NSA ratio
To set the NSA ratio, go to the Building Functions tab in the Metrics Settings menu and set a percentage between 0 and 100 in the table.
