Three Continents under one Roof by Vera Goll | 02.08.2012

Tropenhalle Zoo Leipzig, Gondwanaland

In 2006 a competition for the Tropenhalle Leipzig, named ”Gondwanaland“, was launched. All in all there were 17 participants. The second selection process made the second place design by Henchion und Reuter the winner.

The opening of the tropical building took place after a construction time of nearly four years on June 30, 2011. The large-scale project had required building costs of gigantic 65 million Euro.

Zoo Architecture

In 1994 Martin Henchion and Klaus Reuter founded their first firm in Leipzig. Four years later branches were opened in Dublin and Berlin. Since then many public and private building projects were carried through in Germany, Ireland, Austria and Switzerland. The Tropenhalle in Leipzig is not their first project in the field of zoo architecture. Henchion und Reuter have already designed the Africa house at the zoological garden in Dresden, opened in 2001. In 2009 Henchion and Reuter won the competition for the re-design of the entrance area and the building of a bear facility for the zoo in Frankfurt. The opening ceremony is scheduled for 2012.

Tropics in Leipzig

The concept idea of the Tropenhalle Leipzig was to have three continents under one roof. Inside the hall the development of earth’s history is explained, flora and fauna and the geological conditions of the continents Asia, South America and Africa.

In July 2010 the interior work of Gondwanaland began. Spread across an area of 16,500 square meters a 360 meter long river is going to flow along “all three continents”. From one of the 12 boats riding on the river Gamanil, the versatile stock of small animals can be observed very well. Vegetation consists, among other things, of 415 different, medium-sized tropical trees and other plants, accustomed to the conditions in central Europe through special treatment.

The selection of tropical plants was planned by Berlin-based garden architect Ariane Röntz and installed within three years. This way a botanical garden was created which is among the richest in terms of species in Germany.

Two are better than One

On an area of 2.7 ha there is the 1.65 ha large Tropenhalle, built as a Reuleaux triangle. Its roof has the shape of a spherical triangle. This way the large building volume and its height of 35 meters were able to be realized.

The hall’s structure consists of two frameworks. The primary framework is arranged as a triangular grid. The secondary framework is located below, lowered through tube profiles and based on a rectangular grid. The two frameworks result in a spherical skeleton dome, roofing the building. The roof shell consists of so-called pneumatically spanned ETFE foil cushions. These special cushions consist of three layers of foil, compressed air is pumped into the gaps. In order to establish the required tension and stability, overpressure was generated.

Unique Air-Conditioning

“Our air-conditioning system is the technical core of Gondwanaland”, says Dr. Jörg Junhold, director of Leipzig zoo. “Where ever possible we make use of natural resources such as sunlight, rain water, heat recovery and heat storage.”

Across the year, the nearly 45 different animal species and 17,000 tropical plants require an even temperature and a stable air humidity. A constant temperature is achieved through cooling in summer and heating in winter. The heating and cooling system is based on district heating and heat recovery. On the hall’s roof a solar system has been erected, providing some of the energy. To keep water consumption low, rain water is lead through drainage pipes to tanks where is gets processed. A waterfall is the primary source of the high level of  humidity inside the building. Additionally, water can be sprayed through air gaps in case the humidity is not high enough.

Companies involved in the project:

VEDAG, specialist for flat roof sealings, has been fulfilling these desires for over 165 years now and is thus one of Germany's industrial enterprises with the richest tradition. Apart from that, with a capacity of more than 50 mio. m², the company is among Europe's biggest manufacturers of sealing products made of bitumen and polymer bitumen and supplier of artificial roof sheetings