He is the author of three well-regarded books on historic architecture, "Storybook Style", "Red Tile Style", and "Ready to Roll", all published by Penguin/Putnam. Gellner has also written his "Architext" syndicated column for nearly twenty years. The column has been a regular feature in newspapers such as the Chicago Tribune, Los Angeles Times, and San Francisco Chronicle. Gellner is an honors graduate of the College of Environmental Design, University of California at Berkeley.