Regenwaldhaus (Rainforest House), Osnabrück University Botanical Garden

Osnabrück University's botanical garden opened in 1984 in a former shell-limestone quarry in the Westerberg district. The university later added a large house devoted to the rainforest. According to the press release issued at its opening, the project was paid for with university building funds left over from the institution's founding years: about three million marks, shared equally between the federal government and the state of Lower Saxony, plus some 250,000 marks in donations from Osnabrück institutions and the garden's friends' association for the interior fittings. The state building authority was closely involved.

After two years of construction and planting, the Regenwaldhaus was opened on 13 June 1998, with Loki Schmidt among the speakers. It was meant to serve biological research and to raise public awareness of the diversity of tropical forests. In 2011 the garden gained a second quarry of 2.8 hectares, linked to the first by a tunnel. Closed for about two years during the Covid-19 pandemic, the house reopened on 1 April 2022.

The Regenwaldhaus is a glass structure 21 metres high, built against a rock face of nearly ten metres at the edge of the quarry, above which it stands out clearly. Sources give it an area of about 600 m²; the 1998 press release specifies a usable floor area of about 580 m². The interior is arranged on two levels, connected by stairs and bridges that bring visitors close to the crowns of the tropical trees.

To reproduce lowland rainforest conditions, the house was fitted from the start with high-pressure misting systems and metal-halide lamps. None of the sources consulted names the architect.

The house presents the lowland rainforest of the Neotropics, with an emphasis on Venezuela, Costa Rica and Brazil and, more broadly, on the vegetation of the Amazon basin. The garden lists about 800 species and some 1,000 accessions here. The planting, arranged on both systematic and ecological principles, brings together palms, aroids, orchids, bromeliads, ferns and climbers.

When the house reopened in 2022, the garden's director pointed to several notable flowerings that had appeared during the closure: climbers with flowers of unusual size and colour, Gustavia blossoms visible in the canopy, and bright red, almost spherical flowers growing directly from branches and trunks.

The Regenwaldhaus stands in the garden's first quarry on the Westerberg campus. Its opening times are more limited than those of the outdoor garden and are worth checking in advance. Allow about an hour for the glasshouse and as long again for the rest of the site: 8.4 hectares spread over two quarries joined by a tunnel, with an 11-metre waterfall, an alpine garden, North American and Eurasian forests, medicinal and aromatic plants and a collection of more than 230 species of Allium. The garden receives about 70,000 visitors a year.