In the fifth volume of the CCA Singles series, Hiroshi Hara is in conversation with Mikio Wakabayashi. He revisits his publications from the late 1960s to the mid-1970s on architectural principles — “porous body” theory, “floating architecture,” and “homogeneous space” — and on the surveys he conducted from 1970 to 1980 of vernacular settlements in Europe, Africa, the Middle East, Latin America, and South and Southeast Asia. The conversation is complemented by photographs of project materials in Hara’s office.