The groundwork for Stevenson House began in 1958 with the Unitarian Senior Housing Association. This group, comprised of representatives of Unitarian Churches throughout the San Francisco Bay Area, was established to “determine and provide the means for moderate cost housing in a compatible living environment for the elderly members of the Congregation.“
After an extensive search for appropriate sites, negotiations began with the Palo Alto Unitarian Church in 1964 for 2.2 acres immediately adjacent to the Church. The site was successfully acquired by January 1965. An additional .9 acre was purchased from a private owner at market rate. At about this time, a separate nonprofit corporation, the Palo Alto Senior Housing Project, was formed to operate Stevenson House.
Formal ground breaking took place on September 11, 1966, and the Palo Alto Senior Housing Project Inc. was incorporated as a nonprofit entity with 501(c)(3) tax exempt status in 1967.