He has been the principal of MARK HORTON / ARCHITECTURE, a small office in San Francisco, for the past twenty years where he lives with his wife and four children. He has taught as an adjunct professor at California College of the Arts in San Francisco, and has lectured at a variety of other universities. He is also the cofounder of 2AES: The Art and Architecture Exhibition Space, and the founder of 3A Garage Architecture, a non-for-profit gallery dedicated to architectural art.