Enrico,
This is pretty simple to achieve with a bit of GDL-
select the standard zone stamp and open it up as an object - save as
"your zone stamp"
add a parameter called min_windows and change type to boolean - on/off
Go to the 2d script page and add the following underneath similar code for volume etc.
if winActual then
n=n+1
vlen =vlen + shight
sWinActual= str("%.3",room_winds_surf/8)
Text2 2,-vlen, sWinActual
endif
you can do the same for the required design percentage just add a text parameter to the stamp to take this value and put it in text2 block
-im guessing you want this in to advise for ventillation requirements. The room_winds_surf parameter gives the total area of windows wheither they open or not so you will need to take this into account- there is no easy way of getting that information from a zone stamp.