In large part yes, you are right, his writing was more qualitative and sociological, sometimes philosophy.
But seeing your comment made me start trying to dig up a 1987 paper from Alexander titled, "Toward a Personal Workplace," and I am actually amazed and unsettled by how hard it is to find anything online. That article surveys more empirical properties of office interiors. But yes, I would look to the studies cited in the Peopleware chapter called, "Bring Back the Door" for the empirical extensions of what Alexander had inspired.
Here's the best link I could find on that thread of Alexander's work:
http://zeta.math.utsa.edu/~yxk833/Chris.furniture.html >