Educational Pavilion
Mexican artists Francisco Toledo and Luis Zarate and the anthropologist and biologist Alejandro de Ávila began creating the cultural ensemble that would become the Botanical Gardens of Santo Domingo in the summer of 1994. It would be another four years before they would begin the first phase of planting and six more before they would begin contemplating a greenhouse that could support the growth of those species unable to survive in Oaxaca’s extreme climate.
This diversity was essential to them. They wanted plants that would showcase the ecology of different regions in the state of Oaxaca. They would include those from both arid and humid climates, ranging from the low tropical zones to the temperate and mountain regions. The garden would represent the great diversity of climates, geological formations, and types of vegetation that characterize Oaxaca.
The purpose of this showcase would not merely be to collect a range of species, but also to show how this range of species functioned for the people who lived on the land over the course of several thousand years. In doing so, they hoped to show how the diversity of languages and cultures within the state corresponded to the diversity of plant life and how those plants were used to sustain and enrich human life. This would allow them to create an environment where people could understand how these elements were used for food, firewood, fibers, medicine, condiments, and dyes. Moreover, it would allow people to understand how they have served as a source of aesthetic inspiration, appearing in textile patterns, tiles, and architectural motifs over the course of several thousand years. In this sense, the reason they chose to call the garden “ethnobotanical” was because each element had a cultural meaning.
II. Design
The project came about through a unique invitation from Toledo, Zarate, and de Avila to design an educational greenhouse. The design process began by carefully studying the context via its materiality, texture, pattern, color, and light. It quickly became clear that the Pavilion should reflect rather than compete with this context. It was important to create a lens through which this context could be seen and refined as well as a platform for learning more about this context and its ecology in the future. This involved a detailed conversation with experts to understand the precise growing conditions that would be required for the species grown in the Pavilion. This occurred through ongoing conversations with Alejandro de Ávila. Mathias Schuler and his company Transsolar were instrumental in understanding the thermal conditions in order to design the building systems that would be required to sustain the desired growing conditions.
Following these preliminary conversations, Gonzalez Pulido and Luis Zarate arrived at an initial concept: a two-chambered pavilion whose climates could each be controlled independently. These would be separated by a staircase that would allow the visitor to ascend to the roof. This would not only address the literal program, but also the metaphorical program of the building as one of learning, knowledge, and human connection to air and nature. The building would become more than a single program; it would become an object that would perform in its urban context.
Having determined the form and the structure, the systems and materials that would be employed were refined on the basis of Francisco Gonzalez Pulido’s concept of invisible systems. Werner Sobek further developed the structural system, while Schuler designed the geothermal. At the same time, local craftsmen and material suppliers who ultimately would build the Pavilion were added to the team. Many of these men were from trades in the city that were more accustomed to restoring historic structures. They brought an attention to detail that allowed them to build a highly sophisticated modern work of architecture with the craftsmanship that has defined the buildings of Oaxaca for centuries.
The result is a building that provides a unique experience within the Botanical Gardens through its materiality, transparency, and the way that it frames the garden and the city. It is a reflection of the fragility of life on earth. As an entirely self-sustaining ecosystem, it challenges visitors to consider how they might live in a more sustainable manner as well as to reflect on what is required to sustain life over the coming centuries.
The pavilion expresses greater freedom and sustainability in order to help the inhabitant live a more productive and creative life. It marks a shift from a strictly formal approach to dwelling relying on rigid fixed geometries that can be deployed to any site around the world to an ecological approach that does not merely optimize energy performance or integrate the architectural object into a broader system, but rather manifests the ecology in an architectural language defining materiality, tectonics, and a hierarchy of systems, spaces, and programs.
III. Technology and Aesthetics
The Pavilion is conceived as a contemporary cultural building that, in contrast to its historic context, is designed around the idea of minimum use of resources and minimum environmental impact. It is a self-sustaining “machine” for harvesting. The idea of total transparency was critical in the design. The flooring planks for the staircase and the viewing platform are an open grid to allow light and views from all directions into the chambers. The visual effect that results becomes the central aesthetic feature of the building. The detail with which these panels are constructed, and the overall detailing of the building, is vital in creating a sense of cohesion and achieving a vision that draws on the history of modern aesthetics while also pushing beyond through performance.
The Pavilion never truly vanishes. It is a subtle intervention through glass surfaces and steel detailing that creates new juxtapositions with the surroundings that activate these surfaces in exciting and unexpected ways. The technology that went into the refinement of the glass with minimal reflection and the steel components that hold the Pavilion together is brought into a visual play with the natural surroundings. This contrast between nature and culture, plant life and the mineral product of human refinement creates a framework for understanding both. Hopefully, in the process, the visitor is given a chance to appreciate both with greater depth than when they arrived.
IV. Sustainability and Resilience
The design is based on five elements: the west chamber (“hot chamber”), the east chamber (“cool chamber”), the central staircase (which collects rainfall), the viewing platform, and the “invisible systems” (geothermal, evaporative cooling, and power). The east and west chambers are rectangular glass boxes oriented on the north-south axis to provoke natural cross ventilation. They are located on either side of the central staircase and designed to run on slightly contrasting thermal criteria. The air conditioning is provided through a geothermal system that injects cold air into the chambers.
The Pavilion does not use any power from the city grid to run the fans for the air pipe system and the sprayers for evaporative cooling. The evaporative cooling system of overhead sprayers are mounted at the nodes of the roof structure to create humidity for conditioning and harvesting. The electricity that is required is generated via photovoltaic panels that are mounted on the roof of the main administration building. Due to the sensitivity of the plants, no artificial lighting is required for day and night conditions, further reducing energy demand. The buried air pipe system uses one fan to pull outdoor air through a single intake cavity located in the east wall of the site’s northeast boundary, where the ambient temperature is the lowest throughout the year. The air is then circulated through the buried air pipe network which is approximately 132 meters in length and wraps around the greenhouse 10 meters below grade.
The viewing platform within the perimeter of the pavilion is constructed with a tight steel grating that provides partial passive shading to the interior of the chambers. Flaps located in the north and south elevations as well as on the roof regulate the temperature and humidity. The buried air pipe system and evaporative cooling was critical for achieving this goal.
