Orchid Educational Pavilion, Oaxaca Ethnobotanical Garden

The Jardín Etnobotánico occupies the former huerta, the kitchen garden and orchard, of the Dominican convent of Santo Domingo de Guzmán, whose church and buildings were raised between 1572 and 1666 in the heart of Oaxaca. From the mid-19th century until 1994 the grounds served as an army barracks. On 10 November 1994 an agreement published in the Diario Oficial de la Federación withdrew the former convent from the service of the Ministry of National Defence. While plans for a hotel and a car park were being floated, the artist Francisco Toledo and the PRO-Oaxaca association, which had proposed a garden as early as 1993, succeeded in having the land turned into a public green space. Toledo designed the garden with the anthropologist and biologist Alejandro de Ávila; work began in the summer of 1994 and the garden officially opened to the public in 1998, although some accounts date it to 1993, the year of the proposal.

The orchid pavilion is a recent addition. Commissioned by Fernando García Torres and Alejandro de Ávila, it was designed by FGP Atelier, the practice of the architect Francisco González Pulido, with the engineer Werner Sobek and Matthias Schuler of Transsolar; the artists Francisco Toledo and Luis Zárate are listed among the project's collaborators. Completed in October 2017, it was among the projects of the 2018 edition of the Mies Crown Hall Americas architecture prize.

The pavilion, with a gross floor area of 100 m² over two levels, is glazed throughout and rests on an internal frame of steel pillars. Total transparency was central to the design: the treads of the staircase and the floor of the viewing platform are open grids that let light and views pass in every direction.

On the ground floor, two rectangular glass chambers, aligned on a north-south axis to induce natural cross-ventilation, flank the central staircase: the west chamber is warm, the east chamber cool. The staircase leads visitors through the chambers up to an open platform on the roof, with views over the church of Santo Domingo and the garden. Rainwater is collected and stored to feed an evaporative cooling system. Instead of conventional air conditioning, a geothermal system blows cool air drawn from the ground into the chambers through two air-handling units powered by solar panels.

Most of the building was hand-crafted, made and assembled on site by artisans from Oaxaca. Built from modular units, it can be extended, dismantled or moved.

As its name suggests, the pavilion is devoted first and foremost to orchids. It was conceived as a teaching tool: to provide, through zero-energy sustainable systems, the conditions needed to grow a range of species, while prompting visitors to think about more sustainable ways of living. Its two chambers offer two distinct climates, warm to the west and cool to the east. In 2019 one visitor described it as home to some of the garden's rarest plants.

The pavilion belongs to an ethnobotanical garden, ethnobotany being the study of the relationships between plants and human societies. The Jardín Etnobotánico grows about 1,300 species from some 474 genera and 140 botanical families, and holds around 7,330 accessions, notably in the form of seeds and germplasm.

The garden, about 2.3 hectares in extent, lies behind the Santo Domingo cultural centre in the middle of Oaxaca. It can only be seen on a guided tour; visitors cannot enter on their own. Tours in Spanish last about an hour and those in English about two hours, so it is worth checking the schedule for the language you need in advance.

At the top of the central staircase, the pavilion's rooftop platform looks out over the city and the church of Santo Domingo. A visit pairs naturally with the church itself and the neighbouring cultural centre.