Born in Scotland, Walker received his Diploma in Architecture from Edinburgh College of Art in 1960. In 1958 and 1959 he worked for Swedish architects Jaenecke and Samuelson before moving to the U.S. to study landscape architecture at the University of Pennsylvania. He earned an M.L.A. there in 1962 and then moved to Charlotte, Vermont, to join the Office of Dan Kiley. In 1963 Walker took a brief hiatus and worked in London for Sir William Holford and Partners before returning to Kiley’s office, where he became a partner in 1967. Walker continued working with Kiley for another twenty years as the firm became Kiley Tyndall Walker and later, Kiley Walker. In 1986 he embarked upon his own private practice in Burlington, Vermont.
Walker has been involved in a variety of projects ranging from residential to resort developments, plazas, and large scale regional parks. He completed master plan designs for the University of Kent in London and the National Planning Commission of Canberra in Australia and designed aquariums in Egypt, Singapore, and Korea, a casino in Arizona, and an addition to the National Library of Medicine in Bethesda, Maryland. His work includes commissions in France, Great Britain, Japan, New Zealand, The Netherlands, and the U.S.