Mark was born into the world of the arts. His father, Sidney Simon, was a sculptor, and his mother, Joan Crowell, a writer and composer, inspirations that led Simon to major in sculpture at college. After graduating cum laude in 1968 from Brandeis University, he switched to architecture. Being naturally gregarious, he felt he would be happier working with other people and that architecture might touch more diverse lives than sculpture.

After graduating from the Yale School of Architecture in 1972, Mark initially built cabinets and houses, but then worked in several architecture offices, and was soon hired by Charles Moore, his former teacher and dean at Yale. They collaborated on a number of homes, and in 1978 Simon was named as a partner at Moore Grover Harper, which eventually became Centerbrook Architects.

From the start of his career, Mark has been a pioneer in the practice of “green” architecture, beginning with his design in 1973 of an “Earth House” that was built into a hillside and decades later continues to take advantage of the clean heating and cooling energy of terra firma. Today Mark’s practice ranges from private houses and highly crafted furniture, to commercial, institutional, academic, and religious projects. His projects span from China to Mexico to local projects in New England. Recent houses like the Lakewood house in the Northeast and Casa Ambar in Cabo are explorations in new aesthetics.

Mark continues designing groundbreaking buildings for independent schools like Pomfret, Berkshire, University School, and Keystone Academy in Beijing. He has designed many landmark buildings, among them: LancasterHistory in Pennsylvania; Nauticus – The National Maritime Center in Virginia; Park Synagogue East in Ohio, the Chemistry Building and Business School at the University of Connecticut; Yale’s Kroon Hall (with Hopkins Architects); the Yale Cullman-Heyman Tennis Center; Reese Stadium, the Kenney Center and Jensen Plaza at the renowned Yale Bowl. He is now completing a multi-building Alumni Center for Duke University and leading a substantial team to comprehensively renew and extend Yale’s famed Peabody Museum of Natural History.

Mark's innovative design has been noted by Time Magazine and The New York Times, among others. His 112 architectural awards include the prestigious American Institute of Architects Architecture Firm Award that Centerbrook received in 1998. In 1990, he was inducted into the American Institute of Architects College of Fellows.