The Sacrestia Vecchia or Old Sacristy at the back of the left transept of San Lorenzeo was built by Brunelleschi between 1419 and 1428. Pre-dating the church, the sacristy is the first example of early Renaissance architecture and of the work of Brunelleschi in Florence. A dome covers the square room and a square apse opens off one wall. The structural lines are stressed by stone molding. Eight roundels by Donatello (1435-1443) with the Four Evangelists and Scenes from the Life of St. John are set into the pendentives and the lunettes. The bronze doors and the stucco reliefs over the doors are also by Donatello, while the funeral monument to Piero and Giovanni de' Medici (1472) is by Andrea del Verrocchio. Andrea Cavalcanti made the balustrade of the apse after a design by Donatello, as well as the sarcophagus of Giovanni Bicci de' Medici and his wife. Source: www.arca.net/db/chiese/lorenzo.htm / 'Brunelleschi designed the Sacrestia Vecchia of San Lorenzo ('Old Sacristy' to distinguish it from the 'new' one built in the sixteenth century in the same church by Michelangelo) as a cube surmounted by a hemispherical dome on pendentives, a device he adapted from the Byzantine practice of bridging the corners of the square to provide a circular base for the dome. (The great domed spaces of Renaissance architecture can trace their origins to Brunelleschi's concept.) Ringed by windows at its base, the dome was partitioned by ribs into twelve webs, each with a segmentally curved base line. A smaller cube, similarly vaulted, formed the altar chapel. The dimensions of the sacristy square became the module for the room's proportional scheme linking plan to elevation, and one of Brunelleschi's most influential contributions to the evolution of Renaissance architectural style was the expression of that scheme by the geometric patterns formed by the dark gray stone, known as pietra serena, against the light stucco walls.' Source: Marvin Trachtenberg and Isabelle Hyman, 'Architecture: from Prehistory to Post-Modernism', p 284-5.
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