I mean compute total area by layer.
I explain: I am doing a big project. I put each floor's top face on adifferent layer corresponding to the affectation of the floor (for exemple: exhibition, administration, library etc...). Each time I want to check the total area of library's floor for exemple, I select one face, right click, and go into context menu and choose "by layer" to have the sum of all areas of library's floors top faces. I do that 40 times a day.
I think that if we can make a report of all areas of these faces we can produce an automated area table for elements of program.
Of course it could be done with materials, but we often want to give the same material to all the floors. The differenciation comes with layers.
Switching to "color by layer" mode gives a more analytical vision.
"color by layer mode" = analytical, programmatic
"textured mode" = realistic, rendering.
Sorry for my frenglish.