create a light and ventilation schedule

[amfinishers]

Has anyone created a multi-category schedule with shared parameters? I'm trying to create a light and ventilation schedule which is a code requriement here in IL. Essentially the square footage of glazing in each bedroom needs to equal 8% of the room floor area. SImilarly, the ventilation square footage (window opening) needs to equal 4% of floor area. Seems like X4 should be able to handle this within a schedule. However, I can't figure out how to get the Area parameter into a window schedule so that I can do the math. Grouping and filtering the windows isn't a problem if I use a multi-category schedule (group by room, filter for only windows that have lite/vent variables). But, the area of the room is not an available field in the multi-category shcedule. If I start with a room schedule then I have the Area filed and can create shared parameters but I can't figure out how to bring in the window instances. SOmebody must have done this? This is a fudnamental requirement for all buildings in IL and it would really stink to have to export to excel to do the silly little calculation when it appears X4 should have this capability. Any thoughts would be much appreciated! Thanks.