Since the turn of the century, some architects and engineers have been incorporating more and more sustainable and environmentally sensitive practices into their residential designs. Practices such as passive natural lighting, solar shading, natural ventilation, non load-bearing interior walls, steel framing and pre-fabricated modules. These concepts were responses to environmental concerns that had evolved over the prior 40 years. Oh! I forgot to say that this was the turn of the 20^th century, over a hundred years ago.

Late in the 19^th century, the advent of mass transportation enabled urban families to escape industrial cities and appreciate nature. England passed the world’s first air pollution law in 1863, which was followed by an international air-quality agreement in 1886. In 1909, the International Congress of the Protection of Nature began meeting in Paris.

One of the leading architects in this movement was Antoni Gaudí whose body of work is almost all centered in Barcelona. Gaudí was one of the leading Modernisme architects (the Catalan name for Art Nouveau and not to be confused with Modernism), who took their cues from the undulating shapes found in nature. In parallel, the proto-environmental movement coalesced over the course of Gaudí’s career.

The works of Antoni Gaudí are an exceptional and outstanding creative contribution to the architectural heritage of modern times. The UNESCO World Heritage List (Cultural) includes 832 properties, of which nine are Modenisme architectural properties in Barcelona. Seven of these are Gaudí’s.

In 2014 we visited Casa Milà, the last domestic structure designed by Gaudí’ before he devoted the rest of his life to the construction of La Sagrada Familia that we discussed in an earlier post.

The Casa Milà got the nickname La Pedrera (The Quarry) because of its unusual construction. Gaudí had concrete panels manufactured offsite for installation on the building’s steel frame, demonstrating both a structural experiment and an economically sensible system. It enabled him to have large stone slabs mounted to the façade. This construction system also allowed for large openings in the facade to let natural light into the homes. It also had no load-bearing walls making it was easy to reconfigure interior space. From an architectural perspective Casa Milà is very innovative and includes many features that even today would be considered modern.

Casa Milà is the combination of two buildings structured around two courtyards forming an asymmetrical figure “8”. The “casa con patio” is an effective Mediterranean style for passive cooling. It also provides natural light to all nine levels: basement garage, ground floor, mezzanine, main (or noble) floor, four upper floors and an attic. The main floor was the residence of the Milàs (1,323 m²) and the rest were 20 homes for rent. The attic housed the laundry and drying areas.

In Casa Milá, Gaudí honed the technique of constructing a double “sombra sombrilla” roof. Basically, this structure consists of a series of catenary vaults which create an attic space between two roofs. This space traps air and shades and insulates the building.

One of the most notable elements of the building is the roof. It’s crowned with six skylights, six snail-shaped staircases (that also house the water tanks) and twenty-eight chimneys twisted so the smoke escapes more easily. All of these elements, constructed from brick covered with lime, broken marble or fragments of glass, have a specific architectural function but at the same time, they are also artistic sculptures integrated into the building.

The "mechanical room" for Casa Milà

Chimneys and stairways

Form and function blended in a fantasy

There are also two half-hidden vents in the roof whose function is to refresh the air in the building. These are key elements in using Aeolian and passive solar energy to create a comfortable and efficient building. During the day in Barcelona, the wind blows from inland to the sea but at night that reverses and, the cool sea breezes blow inland. Casa Milà is designed with eastern gaps low in each floor that can be regulated with wooden louvers to cool the structure in the evening. During the day, the sun heats the air under the skylights causing it to rise through the vents and create cross-ventilation across the thermal mass of cool floors in the flats below. In the wintertime the system changes; the eastern gaps are closed and the upper skylights turn the courtyard into a greenhouse. Warm air goes into each flat through courtyard windows that can be opened.

Ventilation shaft

Staircases also camouflaged water tanks

Snail-shaped staircase

Broken ceramic tile decorate a few of the chimneys in moorish head-dresses, a technique called trencadis

Casa Milà is exceptional in that there aren’t any right angles in the design (some commentary suggests there aren’t any straight lines either, but I think that’s pushing the definition of straight a bit too far!). Gaudí was a master at introducing the concept of organic form into his architecture. Casa Milá is unique as it undulates around a city block. The city of Barcelona announced right after completion of the Casa Milà that it was a work of art.

In creating his designs, Gaudí had a very limited tool-kit that would have included a T-square, set squares, a compass and a slide rule—the same tools I had as a student engineer in the late 1960s. But in addition, he relied heavily on physical modelling, particularly to design load-bearing catenary arches. Gaudí hung from the ceiling chains weighted with buckshot in proportion to their structural loads and distance from each other to generate perfectly balanced curves. He then photographed the model extensively and inverted the photos to understand the spacial qualities of the model. Subsequent computer simulations of his models confirm their structural viability.

Gaudí doesn’t get the credit for being the first to use catenary arches in buildings but he is noted for using hanging models like the one pictured to help him with his architectural designs

Model of Casa Milà (La Pedrera)

Antoni Gaudí was a brilliant architect, a structural engineering genius and a green civil engineer. And an artist. Can you imagine what Gaudí could have created if he had the technology that’s available to contemporary architects?

Navigation

UPDATE: Taylor, Kate. “Once considered a folly, Barcelona’s famed Sagrada Familia basilica stands vindicated by time.” The Globe and Mail. July 11, 2021.