[mhays]

TrueViking: I believe your masonry figure is only for part of the enclosure system price, while the curtain wall figure is more inclusive. I'll ask someone at work. But I know that there's no such thing as a $20 exterior for a major commercial building. Part of my question will be about weight difference, and its impact on structural needs.

You're right that natural light is desirable. But my 1889 office building has plenty, with its 50% window coverage above desk level. In fact, most people close their blinds when there's direct sunlight. Personally, I also appreciate that we're not in a fishbowl -- who wants to be on display for people across the street?