The retroactive construction of Architecture: Michelangelo's New Sacristy Wall Drawings

Largely overlooked by scores of passing visitors to Michelangelo’s New Sacristy in San Lorenzo, a series of extraordinary, autographed wall drawings tell the story of a once dynamic construction site. Situated in a small apse to one side of the Medici tombs, these drawings are a palimpsest of over one hundred architectural sketches and drawn constructions in red and black chalk, frozen for centuries into the vertical intonaco surface. Two, true size drawings, depicting the interior and exterior window of the adjacent Biblioteca Laurenziana, are the largest architectural drawings in Michelangelo's remaining drawing oeuvre.

While the drawings have been extensively examined in terms of their role in the project both before and during the execution of the library, there has been no subsequent examination questioning the impact of the drawings on the project after construction. In fact only discovered during renovations in 1976, their unveiling has no doubt reoriented our relationship to the San Lorenzo complex. Within the New Sacristy itself, an entirely new space has been created by them, as one can no longer enter the apse without immersing oneself in the middle of Michelangelo's confabulatory building methods, taking place in true scale, and accompanied by words, markings, and figural sketches (in addition to the glass protector and mounting brackets). At the same time, in their proximity to the depicted details of the library itself, the drawings instigate a cycle of memory and association that intensify the experiential ties between Michelangelo's two projects.

The rather accidental preservation of the New Sacristy wall drawings reveals a magnificent exception to the assumption that construction drawings are useful only before or during construction. In this case, by being 'used-up' in construction and unwittingly archived at the same, the drawings have retroactively altered our encounter with the architecture. In other words, the drawings' power to construct the architecture has endured way beyond their specific utilization by Michelangelo and his assistants in the 1520s.

By comparing this with other examples of on-site architectural drawings, preserved for a variety of reasons, the question of the retroactive impact of construction drawings is examined. (For example, Giacamo della Porta and Domenico Fontana inscribed a true scale section of the dome of St. Peter's onto the floor of San Paolo fuori le mura, a drawing that was removed sometime in the 18th century. However, the drawing probably influenced the construction of 17th century domes in Rome, in particular San Andrea della Valle.) Certainly, the notion of drawing scale and surface are central to these examinations, as well as their fixity to the architecture itself. By broadening the traditional understanding of a construction drawings as devices to translate drawing to building, this paper demonstrates how the life of such drawings can continue to have influence long after the building site has fallen silent.