From a prestigious open space to a green urban oasis: the central square on the Kraneninsel in Heilbronn has been undergoing continuous development since 2019. With a fog system and climatic forest, it is now an urban place to take a deep breath. The offices of K GmbH and uniola AG report on its design in their project presentation.
With an area of around 25,000 square meters, the experimenta in Heilbronn, Baden-Württemberg, is the largest science center in Germany. Here, people of all ages have the opportunity to discover and understand science and technology. The learning and adventure world is located in the middle of Heilbronn’s city center on the Kraneninsel in the Neckaruferpark. The original knowledge exhibition in the historic Hagenbucher warehouse was expanded in 2019 for the Federal Garden Show (BUGA) to include a new building – also on the Neckar island.
Between the old and new experimenta buildings, there is now a space of around 7,000 square meters. The design of this prestigious area, which was completed for the opening of the 2019 Federal Horticultural Show, provides a visual link between the original building and the futuristic new building. Since then, the square has continued to develop both visually and in terms of its functionality, as the following description of the design stages shows – from the characteristic look to the climate-friendly greenery.
The first design plans for Experimenta Square were drawn up by the landscape architects at uniola AG based on the competition concept, which was then implemented by von K GmbH. Since its completion in 2019, the von K GmbH team has further developed the open spaces several times based on the original design. Visually, the square is recognizable: as a homogeneous carpet, it connects the parking areas of the Kraneninsel with the two striking buildings and establishes contact with the Neckar via terraced seating steps in the context of the adjacent water facilities. The small basanite stone paving was laid in a wild pattern (passe) and extends to the adjacent Kranenstrasse to the west, which was rededicated in close consultation with the city. In keeping with the shape of the building, pentagonal inlays of sandstone-like cast stone are integrated into the paved surface, giving the outdoor area an independent character with recognition value. Spread across the square are several tree islands with sparse trees. The polygonal edging, which also serves as seating, picks up on the architectural thread and continues it harmoniously. At night, the outdoor area is set in an atmospheric setting: pole-mounted luminaires of different heights illuminate the buildings and the entire square.
Even after BUGA 2019, the landscape architects at von K GmbH played a key role in the successive design development of the experimenta site and Kraneninsel. The office was commissioned to develop the new planting and maintenance concepts: the task was to convert the approximately 900 square meters of alternating flora on the heavily frequented square into a permanent installation and to coordinate the work. To this end, the von-K planners modified the arrangement of the beds and planted them with near-natural shrubs, perennials and early-flowering bulbs. They also redesigned the existing tree islands and restructured the paths. Thanks to its central location, the prestigious, ecologically high-quality site is a much frequented place in Heilbronn with a high quality of stay even after the BUGA.
In order to optimize the average maintenance effort, the vegetation areas on the Experimenta square are now watered using an intelligent system: the modern control system is not based on a conventional timer, but uses meteorological weather data. This means that the plants are only watered when it is really needed – for example, not when heavy rainfall is expected. This also minimizes water consumption.
Cities and municipalities – especially densely built-up inner cities – are increasingly becoming heat islands due to the rise in temperatures caused by climate change, particularly in the summer months. Sustainable and dynamic urban development therefore requires numerous well thought-out measures that focus on climate protection and climate resilience: More greenery, more water, less asphalt and concrete contribute to a better microclimate and thus ensure a better quality of life. The clients’ decision to erect an AI pavilion on Experimanta Square also made it possible to rethink the entire open space with a focus on climate resilient conditions. In a very short space of time, the proven collaboration between uniola AG and von K GmbH resulted in an unparalleled enhancement of the square. According to the motto “Experimenta Square should become greener”, the redesign takes into account the climatic and sustainable requirements and also contributes to improving the overall inner-city climate in Heilbronn. In the new AI pavilion, everything now revolves around the topic of artificial intelligence (AI). Visitors can gain an exciting insight into the technology and test AI applications on site.
The necessary redesign of the square is once again based on a concept by the landscape architects at uniola AG; Büro von K was responsible for the implementation of all service phases as part of a consortium. In order to sustainably improve the quality of life and air in the city center, the previous paved area was unsealed as far as possible to create space for green islands with a cooling forest character.
For the planted oases, there was a desire for them to inspire with a varied and preferably flower-rich appearance all year round and to offer a wide variety of species. When selecting the trees and shrubs, it was also important to consider that they had to be able to cope with the extreme site factors: Parts of the Experimenta square are built under and therefore offer little root space. The sealing and reflective façade walls also ensure a high level of heat development, especially in the hot season. For this reason, the two forest oases have been raised (around 1.20 meters) on modelled terrain. A special lightweight substrate reliably supplies the planted greenery thanks to its high water retention capacity. When selecting the trees and shrubs, Büro von K had both the native flora and fauna and climate change in mind: So-called “future trees” were planted in the two tree areas of the square – i.e. those that can adapt to changing climate conditions or are known to cope well with extreme climates such as drought. Where possible, native plants were chosen. The result is a so-called “climate forest”, in which some of the original willows can be found, as well as Scots pines, Himalayan birch, serviceberry and red maple for colorful accents. Small shrubs such as copper rock pear and winter honeysuckle complement the planting, as do drought-resistant grasses. Evergreen shrubs such as the fragrant blossom also ensure attractiveness in winter.
In addition to the woodland planting, a flowering meadow was also created to preserve biodiversity. The colorful meadows – some with wildflowers as well as herbs and grasses from native seeds – provide insects and other microorganisms with much-needed nesting and living space as well as a wide range of food; at the same time, they are a feast for the eyes for walkers and passers-by. The partial unsealing of the square has also created more open areas that allow better rainwater infiltration.
Also with a view to improving climate resilience, a misting system now cools down passers-by on hot days. The humid air also has a positive effect on the environment: the timed water mist can lower the outside temperatures in the immediate vicinity by several degrees – the positive effect is particularly noticeable and useful near STEIN surfaces such as floors and facades.
As part of the redesign of the Experimenta square, von K also took on the traffic system planning for the Kraneninsel (load class 3.2): This included the planning of a traffic light system, the optimization of the road width as part of the unsealing measures and the creation of passing places for trucks. The von-K landscape architects also integrated a parking facility for autonomous buses into their concept and – in coordination with the fire department, the city of Heilbronn and the operators of experimenta – developed a safe access control system that only allows experimenta employees and the city administration to access the Kraneninsel. The use of bollards controls the access of delivery vehicles and allows them access to the square. Anyone wishing to access the area must authenticate themselves using a chip or ring the bell. Automatic vehicle license plate recognition is also possible.
Since the redesigned Experimenta Square was inaugurated in June 2024, visitors have shown that the local improvements to the climate have been successful and well received: On the hot days in summer, passers-by have stood in the spray mist to enjoy the cool refreshment. Those who need a short break to rest can now find a seat in the shade of a tree. A long-term measurement of the temperature and climate development on the square is also planned; in addition to the subjectively perceptible improvements, this will also provide measurable results on the cooling of the area.
Designing outdoor spaces sustainably, creating green and open spaces for well-being and planning individual gardens – this is what von K Landschaftsarchitektur does with passion and expertise. Founded in 2017 in Ostfildern, Baden-Württemberg, the young company is based on the Filder plain. From there and remotely, around 20 employees work on projects far beyond the Stuttgart metropolitan area; since 2024 also at the second location in Denkendorf, where von K has created space for a dynamically growing team.
The von K landscape architects have made a name for themselves with their high standards of quality, creativity and attention to detail. Their core values and way of working are also well received: Von K scores points for reliability, adherence to deadlines, professionalism and fairness. Private, commercial and municipal clients value the office as experienced consultants and planners of economically well thought-out and authentic landscape concepts. Major showcase projects are proof of this. These include, for example, the design of the educational campus and the square surrounding the experimenta learning and experience world in Heilbronn for the Dieter Schwarz Group.












