A historian of Late Antique and medieval architecture, Professor Smith focuses her research upon Italian church construction, liturgy and architecture, and pre-modern architectural theory and texts. She is the author of a number of books, including The Baptistry of Pisa (Garland, 1978), Architecture in the Culture of Early Humanism (Oxford University Press, 1992), (with Joseph O'Connor) Building the Kingdom: Giannozzo Manetti on the Material and the Spiritual Edifice (MRTS, 2006), and (with Joseph O'Connor) Eyewitnesses to Old St. Peter's: Maffeo Vegio's "Remembering the Ancient History of St. Peter's Basilica in Rome" (Cambridge University Press, 2019).