Unity Temple is a Unitarian Universalist church in Oak Park, Illinois, and the home of the Unity Temple Unitarian Universalist Congregation. It was designed by the American architect Frank Lloyd Wright, and built between 1905 and 1908. Unity Temple is considered to be one of Wright's most important structures dating from the first decade of the twentieth century. Because of its consolidation of aesthetic intent and structure through use of a single material, reinforced concrete, Unity Temple is considered by many architects to be the first modern building in the world. This idea became of central importance to the modern architects who followed Wright, such as Ludwig Mies van der Rohe, and even the post-modernists, such as Frank Gehry. In 2019, along with seven other buildings designed by Wright in the 20th century, Unity Temple was added to the UNESCO World Heritage List. The Unitarian Universalist congregation that worships in Unity Temple was formed in 1871, and has no connection with Unity Church, a religious organization founded in 1889. Background In 1905, a lightning strike started a fire which destroyed the wood-framed Oak Park Unity Church, architect Frank Lloyd Wright was one of the many architects who vied for the commission, and was ultimately selected to design a new structure for the Universalist congregation of Oak Park, Illinois. The result was the Unity Temple. Wright was not only living in Oak Park but also came from a family of Unitarians, a faith that had many beliefs in common with Universalism. The congregation needed a space of worship, as well as a community room. There were several immediate problems that the architect had to work with in order to satisfy the client. The budget was $45,000, a modest amount even in the early 20th century. Building materials had to be inexpensive and as Wright said, “concrete is cheap.” The same concrete molds were used multiple times, as Wright had designed repeating walls with similar dimensions. Additionally, the building site stood on a busy street. And finally, the architect was expected to design not only the structure but also furniture and stained glass for the building. Charles E. Roberts, an engineer, inventor and an important early client of Frank Lloyd Wright, served on the church's building committee and was a key figure in seeing that Wright's vision for the church became a reality. For Roberts, Wright also remodeled Roberts' home and the