First Unitarian Church was constructed between 1959-62, with an attached two-story with basement brick-clad addition that was built in 1965-69. The two-story building is of steel reinforced concrete block and poured concrete construction and is clad in brick on its exterior. It features a binuclear plan, with two larger units joined by a hyphen that serves as the main entry. Designed by prominent national and international architect Louis I. Kahn, First Unitarian Church is an excellent example of his Modern architectural style. During his design process for the building, Kahn’s theories of “form and design” were fully developed, and the church served as the basis for what is regarded by many scholars as his most famous lecture, “Form and Design,” which he delivered in 1960 before ground had even been broken for the project. First Unitarian Church can also be viewed through the lens of his later theories on “silence and light,” with its stunning and controlled use of indirect lighting.