We had a good Revit question come in from our Dubai office this morning concerning the calculation of gross floor area in a mass. What could cause a mass object to not list any gross floor area in the Properties palette?
First, you must ensure that at least one Mass Floor is selected. You can access this setting by selecting a mass element and then clicking on Mass Floors in the contextual tab of the ribbon.
In this case, one level was selected – but the level was NOT intersecting the actual mass element.
This is a bit of a limitation if you are using Revit for urban design or master planning on a hilly site. You will need to create at least one level for each plateau of buildings in order to utilize the Gross Floor Area property.