Botanical Garden, Karlsruhe, DE
Glazing with GEWE composite®
Since spring 2018, the three historic show greenhouses of the Botanical Garden in Karlsruhe have presented themselves and their plants almost as they did in the 19th century. The cold house, palm house and warm house were extensively renovated in terms of design and construction in a four-year construction period according to the specifications of the monument preservation. Particular importance was attached to glazing with laminated glass of the special GEWE-composite® from Schollglas. It is characterized by a transparent, particularly lightweight plastic core that is very resistant and also extremely weather- and age-resistant.
The Botanical Garden as a complete ensemble with the Orangery and the State Art Hall forms the green oasis in the heart of the city of Karlsruhe. In its first form with a castle and castle garden, it has existed since the city was founded at the beginning of the 18th century. The Botanical Garden became known throughout Europe for its diverse plant population, especially the rare citrus species and dahlias.
Project data
Client
State of Baden-Württemberg
Planning, tendering, awarding, construction management
Architectural office ruser und partner mbb, Karlsruhe, DE
Landscape Architecture Office Helleckes, Karlsruhe, DE
GEFOMA, Großbeeren, DE
Construction
GTW Gewächshaustechnik Werder GmbH, Glindow, DE
Products
usedGEWE-composite® for laminated and patterned glass
Glass supplier
Schollglas GmbH Zweigniederlassung Glauchau, Glauchau/DE
Historic core, modern products
In 1806, the Karlsruhe master builder Friedrich Weinbrenner began to produce the first drafts for the new creation of a botanical garden. Under Grand Duke Friedrich I, building director Heinrich Hübsch then implemented the plans from 1853 to 1857. He had the show greenhouses built as wooden structures. Only a few years after the death of Heinrich Hübsch, between 1863 and 1871, the houses of Dyckerhoff and Berckmüller were replaced by a mild iron construction.
The complex, which was badly damaged in the Second World War, was rebuilt in the 1950s with simple means and changed again for the Federal Garden Show in 1967. In recent years, there have been structural problems with the construction, which prompted the owner of the Botanical Garden, the state of Baden-Württemberg, to carry out a large-scale renovation of the ensemble.
On the basis of old sources from the General State Archives and preserved original plans by the court architect Heinrich Hübsch, it was possible to restore the show greenhouses to their original appearance. In addition, all figures on the outer façade were restored, the iron construction with its typical structural details was restored, the natural stone walls were renovated and, in particular, the glazing was renewed. In particular, it was important to implement the requirements of monument preservation.
Laminated glass with high UV transmittance
The demanding plants require different radiation spectra from different ranges of visible light for their growth. The GEWE composite® used offers an optimal amount of light for the plants in the greenhouses due to its high degree of radiation transmission. At its site in Nossen, in cooperation with the branch in Glauchau, SCHOLLGLAS produced a total of around 525 square metres of composite glass of the special GEWE composite®. It is characterized by a transparent, particularly lightweight plastic core that is very resistant and also extremely weather- and age-resistant. In addition, the GEWE composite® core has an extremely high residual load-bearing capacity and is itself a structural component of the composite. Another decisive advantage for this project is the high UV transmittance. A normal laminated safety glass only allows about 1.2% UV radiation into the interior of a building. For the GEWE composite® used, this value is up to 63.2%.
Small-scale patterned glass sets technical accents
Another special feature of the glazing of the greenhouses was the use of patterned glass. The type “cathedral small hammered” was used. This glass structure cannot be processed into laminated glass with the commercially available composite processes via film interlayers, but it offers the desired, necessary optimal privacy protection that still allows enough light into the interior of the greenhouses.
Conventional, non-structured lenses often offer no protection against spot light. The operators of the botanical gardens therefore need additional shady elements so that the sensitive plants do not burn. For this reason, those involved in the construction once again opted for the GEWE-composite® product.
The laminated glass consists of a float pane, an or-name pane and the transparent plastic core, which glues the two individual panes together to make them shear-resistant. During production, it was also necessary to take into account the sometimes very small dimensions of the glass panes due to their design, as well as their formats, such as triangles. With these 712 panes, the insertion of the plastic core had to be mastered. Due to the special conditions on site, tempered glass (ESG) was also used for some of the elements.
As a result of the restoration, the Botanical Garden is once again perceived as sophisticated garden architecture. The show houses of the complex include the Cactus and Succulent House, the Palm House and the Tropical House.
Today, the various greenhouses house the most exotic plants from the most diverse climates. Visitors can also view sculptures and aviaries with exotic birds.
