Short answer: As long as you can claim that glass is almost nothing.
Long answer: Ever since the Gothic era, glass has scored points for its invisibility. Walls of glass are often described using words such as openness, transparency, and participation. But those words are more compelling than the reality. In practice, a glass building can be just as forbidding as a blank wall. Glass buildings are as tangible as others and must be treated as such. We used to rely on window muntins to give form and substance to glass, weaving together the wall across the window opening. If glass is going to make up the whole wall on its own, it also has to be able to be something. That requires more than just wanting to be nothing.
This short excerpt was taken from Rasmus Wærn & Gert Wingårdh's new book, "What is Architecture? And 100 Other Questions." This week, we're sharing seven questions from the book, with one new excerpt released each day. "What is Architecture? And 100 Other Questions" will be on sale starting September 1st.