Unity Temple, designed by Frank Lloyd Wright and completed in 1907, is constructed with a structural system comprised almost entirely of reinforced, cast-in-place concrete. The incorporation of an exposed pea-gravel exterior aggregate is one of the first uses of an architectural concrete finish in the United States. The original design of the concrete elements of the building has significantly affected the serviceability and appearance of the structure. Cracking and deflections have been noted over the life of the structure. Previous repair programs involved coating the exterior walls with a polyvinyl acetate bonding agent during the 1960s. In the early 1970s, the original exposed aggregate surface was removed from most of the exterior wall area and a shotcrete coating was applied. This new surface was then treated with linseed oil. This paper describes the original construction, previous repair programs, and current investigation program. The recently completed initial phase of the investigation was implemented to evaluate the existing condition of the original materials and the newer shotcrete surfaces and to develop a program of testing to determine appropriate methods of repair and restoration for this historic structure.