The Medici owned a vast collection, six hundred manuscripts in all, an unprecedented amount at that time. This collection by the Medici was later moved to Rome, but Clemens (Giulio de’Medici) decided that a new library was to be constructed at the Palazzo Medici-Riccardi and their church, the San Lorenzo, and it would store the family collection.
The library of Michelozzo as a prototype for the Laurentian
Michelozzo had already built a library for Cosimo de Medici on the first floor of the San Marco. This library, inside the San Marco monastery, was one, elongated small hall. Two arcades with Ionic columns divide the space up into three naves. The slightly wider and higher centre-most nave has a barrel vault. The aisles have groin vaults. On both sides, each bay has a window to achieve a high level of natural lighting, which certainly comes in handy when reading manuscripts and miniature books. This library would be the standard for many other libraries. When Michelangelo is commissioned by pope Clemens VII to design a new library, he uses the design of his predecessor Michelozzo.
The Laurentian inside an already existing cloister of Michelozzo
Michelangelo too was allowed to build his library at the Piazza San Lorenzo. He would thus have complete freedom over his design, but he decided not to opt for the lot opposite to the facade of the San Lorenzo, the very lot for which Brunelleschi once designed a palace for Cosimo. Buonarroti was still hoping for a chance to build the facade of the San Lorenzo. He likely feared that a library opposite to it would have a detrimental effect on the facade. Finally, he decided on the cloister’s courtyard, but in doing so, Buonarroti made it rather difficult for himself. After all, now he has to work inside an already existing building that was constructed by Michelozzo.
Laurentian: beauty versus functionality
Modern architecture often reproaches Renaissance architects for being too focused on a beauty standard (proportio, symmetria and so forth) and paying too little attention to the functional aspects of a building. The twentieth-century American architect, Frank Lloyd Wright, formulated in this sense the adage of modern architecture: ‘form follows function’ This principles implies that the classical ‘grammatical rules’, which are not based on functional principles, must be rejected. What is functional, has beauty. The many sources and letter exchanges between pope Clemens VII and Michelangelo reveal how much attention was paid to the practical side (function). Michelangelo had to account for many tricky requirements and conditions. For instance, there was and were to be:
1. Sufficient lighting. A first floor with highly-situated windows that provide a lot of light therefore makes for an interesting solution.
2. No damp air because of the books.
3. Heavy stone vaults that support the library, creating sufficient fire protection.
4. A building constructed inside an already constructed cloister by Michelozzo. This brings with it a wide range of issues.
5. Sufficient space for books and reading areas.
6. Two departments: for Latin and Greek.
7. A nice link of the ricetto or vestibule to the higher library hall.
Many sources and drawings of this library have remained intact, so we have a good understanding of the design and construction history. Clemens VII wanted to optimally protect the library against fire and therefore it was supported by stone vaults.
The reading room
The reading room was to be placed above the vaults on the first floor, like with Michelozzo’s library. In doing so, Michelangelo had no choice but to fortify the old walls, but without making them too thick. The exterior of the library, at the side of the courtyard, clearly shows the flat ‘buttresses’ between the long series of windows. At the outer-most wall on the west side, Michelangelo used a Roman method to fortify the walls: a series of rounded blind arches.
The load-bearing construction is also easily seen in the library room itself. Buttresses have been placed between the windows, with pietra serene pilasters at the front to make the load-bearing construction even more solid. These are pilasters that this time actually have a load-bearing function. The buttresses have determined the rhythm of the space. In this regard, the reading room is reminiscent of Gothicism where the (stained) glass windows were also placed between the supporting bundled pillars and buttresses. Naturally, Michelangelo made use of contemporary windows that are put relatively close together and continue up until the benches. The walls with the windows between the buttresses are no more than 30 centimetres thick. The load-bearing elements not only determine the division of the bays, but also the ceiling.
In early Renaissance, there was no connection between a ceiling and the wall plane (Wikipedia). Clemens VII was the one who demanded that the ceiling should look different from the ceilings in the Vatican. The drawings of Buonarroti were not entirely to Clemens VII’s liking as they showed no logical link between the wall segments and the coffered ceiling. In the actual, final ceiling, the cross beams end up exactly at the buttresses. The two long beams that run through nearly the entire length of the reading room also end up exactly at the pietra serena pilasters next to the doors. The ceiling itself barely needs support. The roof trusses for the saddle roof above the wooden ceiling, however, do need support. The floor receives the same pattern as the coffered ceiling, establishing a clear link between the walls, the ceiling and the floor (Wikipedia).
The benches, which Buonarroti first placed separate from the walls, are also included in the load-bearing system, albeit optically.
For his first design drawing 1524 [Casa Buonarrti, 42Ar] of the reading room, it is clear that Michelangelo started out by using heavy sculptural walls. In his later designs, the wall plane is increasingly being reduced into a flat wall in which recesses and windows have been installed. The walls between the pilasters skip back a little compared to the load-bearing parts. In this respect, Michelangelo is following a typical Florentine custom: a tradition of a delicate wall segment that emphasises the flat wall plane. The latter is again amplified by white plastered walls. This is strongly reminiscent of the architecture by Brunelleschi in his Old Sacristy or the Pazzi chapel, but can also be seen in a Gothic church like the Duomo. The frames around the windows seem to be just lines instead of heavy, sculptural shapes. The balustrades in the recesses above the windows do not protrude from their surrounding frames despite their strong, sculptural shape.