Per 2009 CI you cannot count any glazing area below 30". Is it safe to assume that if a 42" file cabinet is placed in front of the window (not my design) that you can only include the area above 42"? As a side bar; the glazing is full height at 9' with a 2" frame...do I start my 63 degree angle from the 9' mark or from the 8'10"? Also, when calculating the glazing area do I subtract any other vertical or horizontal mullions?