Casa Sperimentale – A Baroque Geometry

Giuseppe Perugini’s analysed Francesco Borromimi’s Church Sette Dolori using a geometry based on circles and their numerical dependencies. Using a similar technique it is evident that the geometry of the Casa Sperimentale followed similar patterns. (Drawing by Patrick Weber)

Giuseppe Perugini was Professor for Architectural Composition at Roma Sapienza University. His main field of research focussed on the Baroque architectures of the architect Francesco Borromini (1599-1667). Perugini developed an analytical drawing method used to study the compositional arrangement of two projects through geometrical drawings.

In the first one, the church *San Carlo alle Quattro Fontane*, he predominantly applied the technique to the plan arrangement of the main space. In the second, the convent *Santa Maria dei Sette Dolori*, this tool was used in plan, section and as well in the details studies of individual architectonically relevant fragments like for example the entrance portico and the oval side niches.

In his book *La Forma in Architetture* published 1953 Perugini explored the idea of introducing geometric tools to analyse architectural form of the buildings. He concluded that this process, although removed from the actual experience of the space, is clearly ‘a result of a wise will, of a practical convention of the mathematizing mind.’ (p21)

In a further publication *Architettura di Borromini nella Chiesa di S. Maria dei Sette Dolori (1963) *he sets out a baseline grid formed of numerically related circular geometries to analytically interpret the space. He concludes that “the geometric repertoire of Borromini does not originate from emptiness; it has its roots precisely in that primordial geometry of the plan.” (p23)

Perugini was not explicit in documenting his translation of the Baroque projects taken as studies to his contemporary design outputs. This is partially due also of the organic nature of the design process especially in the Casa Sperimentale, in which very few drawings were used or survived. Whereas in his early designs, notably the reconstruction of the San Germano village in 1955, he mainly relies on a composition based on the application of the *Golden Section*.In mathematics, two numbers are in the golden ratio if their ratio is the same as the ratio of their sum to the larger of the two number. This ration can be expressed as 1.618… It is evident that in the Casa Sperimentale Perugini experimented with both an arithmetic number sequence, and an order based on the Fibonacci Sequence of numbers. There is evidence that these were derived from his detailed geometric studies of the *Santa Maria dei Sette Dolori* Church in the plan and section studies.

Noting that Baroque spaces have many layered and possible interpretations, even beyond architecture, we can see Perugini’s arc of interest focussing on the plan and the elevation, then identifying trigonometric patterns of proportions—operating at different levels—used to order recognisable undulations of wall and structure in plan, and architectural elements such as windows and arches in elevation. It is understood that these studies were not conducted specifically with the Casa Sperimentale at a singular objective and so, tracing possible reinterpretations and applications of these qualities, from his studies to his designs, provides an interesting exercise.

In conducting a comparative study of the Casa Sperimentale we can observe specific tendencies, which highlight or at the very least suggest tangible influences of his Baroque learning on his design principles. These include a rhythmic use of proportion at differing scales to define rooms, the use of undulating walls, and light, to dissolve the idea of a flat building perimeter, and the use of line, square, and circle in specific combinations, subtly echoing Baroque compositions.

The outer walls of the Casa Sperimentale are composed and constructed out of individually precast concrete frames. Each wall has a different tectonic and elevation. (Drawing by Patrick Weber)

The numerical relationships in the relation of the individual building elements and their compositional arrangements are based on an arithmetic number sequence. The relationships seem to echo the ones researched in Sette Dolori. (Drawing by Patrick Weber)

The numerical sequences and relationships of the parts to the whole arrangement allow for a near-infinite number of unique arrangements of the parts within the set parameters of the exterior walls. This drawing shows these relationships within the perimeter walls drawn as arithmetic number sequences. (Drawing by Patrick Weber)

This drawing investigates the walls of the Casa Sperimentale through the Fibonacci number sequence 1-1-2-3-5-8-13. (Drawing by Patrick Weber)

This drawing investigates the walls of the Casa Sperimentale through an arithmetic number sequence 1-2-4-8-16. (Drawing by Patrick Weber)

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July 5, 2020