Equatorial Dome, ZooParc de Beauval

The ZooParc de Beauval, at Saint-Aignan, built its reputation on a series of tropical glasshouses: the great apes house in 1992, the bird house in 1994, the manatee and gorilla house in 1997 and the Australasian house in 2002. The Equatorial Dome is the culmination and by far the largest. Its client was Rodolphe Delord and its architect Daniel Boitte, with the CSTB and the CTICM as engineering consultants.

Work began in October 2017. The contractor CMF carried out the roof framing, the cladding and the control of the interior climate; the structure was complete in early 2019 according to one account, and fitting-out, planting and the pools continued into early 2020. The dome opened to the public on 8 February 2020, a date that coincided with the park's fortieth anniversary.

The cost is given as 40 million euros by two sources. Accounts diverge on several figures: the area (8,000 m² of floor, 13,855 m² of total envelope, 15,000 m² according to the regional press), the target temperature or the number of plants. The design is that of a half-sphere symbolising the Earth cut at the equator, with a route that follows a gentle slope.

The dome is a fully glazed half-sphere, more than 100 metres across and 38.24 metres high, with a floor area of about 8,000 m² (13,855 m² for the whole footprint). Its primary steel frame weighs about 1,000 tonnes and rests on 48 truss half-arches, pre-assembled in the factory and then erected on site; the shell is divided into 144 facets, some of which exceed 100 m² and weigh more than ten tonnes.

The aluminium profiles, from the Ecoklima range, are thermally broken. The double glazing receives three different treatments of light transmission and solar gain depending on orientation. Heating combines low-temperature floor circuits and unit heaters; optimised natural ventilation is supplemented by air destratifiers, a high-pressure misting system and controls driven by a weather station. The target temperature is between 26 and 28 °C depending on the documents consulted.

The one-kilometre spiral route crosses equatorial habitats of South America and Indonesia, according to the regional press. About 2,000 trees and 20,000 small plants, brought from the Netherlands, make up the vegetation: tree ferns, ficus, banana plants, bamboos and palms. The dome has some twenty pools, artificial rivers and waterfalls, and rain is simulated every night.

Sources speak of about 25,000 animals of 200 species, most of them, some 24,000, fish and amphibians. Residents include Caribbean manatees, giant otters, Komodo dragons on beaches heated to 40-50 °C, pygmy hippopotamuses, golden lion tamarins, harpy eagles, Rodrigues fruit bats, false gharials and red-shanked douc langurs, a threatened primate. The manatee pool has a viewing window 23 metres long, presented by Mag'Centre as the largest aquarium window in France.

The dome stands inside the ZooParc de Beauval, and its visit is included in the park's admission. The suggested duration is about two hours, along a gently sloping route that offers many viewpoints on the animals. The dome also holds a panoramic restaurant and can receive about 3,000 visitors at once.

The interior stays warm all year, which makes it a pleasant stop in winter. Enthusiasts of glass architecture can add the park's other tropical houses, older and smaller, devoted to great apes, birds, manatees and Australasia. The park is at Saint-Aignan, in the Cher valley.