Architecture from Brunelleschi to Alberti

Brunelleschi: Architect of the Renaissance

Florence Cathedral (Cathedral of Santa Maria) Brunelleschi: Dome of the Florence Cathedral, beg. 1420

Although he trained as a sculptor and jeweler, it was his extraordinary knowledge of engineering that allowed Brunelleschi to become a model architect.  Brunelleschi's achievements were renowned during his own lifetime, an unusual accomplishment at a time in history when newspapers and radios did not exist.  In honor of his achievements, he was buried in the Cathedral of Florence and he was the subject of the first full-length biography written about an architect (written approximately 40 years after his death).

The Cathedral Dome relies primarily on Brunelleschi's skill as an engineer. The drum or base of the dome was already in place before Brunelleschi received the assignment to complete it.  The span of the octagonal drum was 140 feet, a very large span for a dome at that time, especially one without the possibility of external buttressing or supports.  Brunelleschi knew that a hemispheric dome (one which is  perfectly rounded) would not be able to span this distance without the use of external buttresses.  As a result, he decided to make a pointed dome.  He placed 8 major ribs at the points of the octagon, and 16 minor ribs (two in the space between every two major ribs), all tied together by lateral bands. The dome was double-shelled (the first one, in fact), with brick near the top, rather than stone, laid in horizontal courses one row at a time, which meant that each row carried the weight of the next one. This was an ingenious solution because each row became part of the scaffolding necessary to reach the top.

Brunelleschi's "sister" churches: San Lorenzo and Santo Spirito

Brunelleschi: plan of San Lorenzo, begun in 1421 Brunelleschi: plan of Santo Spirito, beg. 1436

The plan view for San Lorenzo shows how Brunelleschi conceptualized the modules of the aisles. In each bay, the dome meets the corners of the square.  It's as if the architect has pulled or stretched the dome in four places in order to make it meet the walls in the four corners of the square.  But the person who's standing there would perceive the space as a billowing circle or umbrella-like cloud overhead.  Most people, in fact, did describe Brunelleschi's architecture as supremely lucid, rational and serene, precisely because they could perceive the geometric relationships.  This was an important contrast to Gothic architecture, which was, without doubt, exquisitely beautiful.  But the soaring spaces of a Gothic cathedral were intended to awe and mystify the viewer with the transcendent beauty of the sacred.  The Renaissance church, in contrast, wanted to communicate the idea that math and science were paths to the sacred.

In plan, Santo Spirito suggests that Brunelleschi was going to try to express a similar idea in the overall shape of the building, making for a more sculptural surface.  He did not live to complete it, and it was not finished according to his plan.  In fact, it was finished in much the same way that San Lorenzo was completed.  The interiors of both churches also look remarkably similar.  They are not the same size and there are slight differences in shape and decoration but the differences are hard to see.  In class, we looked at Santo Spirito.

nave of San Lorenzo, facing east

In the Pazzi Chapel, Brunelleschi used the square module of the crossing bay (the central bay under the dome) as the basic unit for the whole plan.  There is a degree of rationality to it which can be perceived without knowing the measurements.  Although Brunelleschi did not invent the golden section, one of his major accomplishments was the creation of mathematically lucid space in Renaissance architecture.

Brunelleschi: Pazzi Chapel, Florence, beg. 1433 plan of the Pazzi Chapel

Just as perspective was used by the Italian painters to lead the viewer to focus on the head of Christ or another significant religious moment in a painting, in architecture, mathematical precision and clarity likewise led the eye to the spiritual. When you look at the facade, plan, and interior, note how each view is almost identical in terms of the use of the module and the sense of rationality to the design.  Brunelleschi goes further, in fact, by almost "drawing" perspective in his architecture through the designed recession of the window openings, the markings on the floor, and the repeated use of similar forms but on an increasingly smaller scale.

interior view of Pazzi chapel

Alberti's "solution" to the west end of the church

In his churches, he tried to develop the solution to the problem of the west end of the church.  The problem involved the difference in height of the aisle and the nave.  Should this difference be reflected in the facade?  Or should it be hidden?  Sant' Andrea in Mantua represents one solution, of interest because it combines references to ancient Roman architecture and ancient Greek in the same facade.  Yet the church is more notable for the grandiose interior, which repeats the form of the triumphal arch and which became a model for important churches of the late or high Renaissance.  At Santa Maria Novella, he relied on a more harmonic and mathematical approach, arriving at the idea of the scroll which bridges the height from the lower aisles to the higher nave. Whereas Sant'Andrea will be more influential to architects in the 16th century, Santa Maria Novella became the dominant model for Renaissance church facades in the 15th century.
Alberti: Sant' Andrea of Mantua, 1470 interior view of Sant' Andrea Alberti: Santa Maria Novella, Florence, 1458-70