Innovative sculpture: St. Pölten‘s breathing oasis made of concrete and bricks

A fascinating work of art is raising at Europaplatz in St. Pölten since September 2024 – it is far more than just an aesthetic enrichment of the cityscape. The so-called „Windfänger“ (vestibule), a creation of the „Breathe Earth Collective“ artist group, epitomizes the perfect symbiosis of art, engineering art and ecological consciousness. With a diameter of 13 meters and a height of more than four meters, the sculpture presents itself as an open rotunda which not only delights your eyes, but also actively contributes to improve the urban micro climate.

Concrete meets tradition: A touch of the Orient in Lower Austria

The inspiration for the „Windfänger“ structure range from the Arabian mashrabiya to the Egyptian cooling techniques through to the Alpine brick lattices. The cross-cultural conflation is reflected in the unique structure, consisting of „monk and nun“ style tiles – supported by strong concrete beams.

Due to the special bricks and tiles and an incorporated irrigation system, a space is created that is permeable to air and light and that provides a habitat for birds and insects. While the sculpture helps to reduce traffic noise and particulate matters at a busy crossroads, simultaneously.

The combination of concrete and bricks turns out to be an ideal solution for the complex requirements of the project. Concrete, known for its moldability and stability, enables the realization of a demanding geometry, whereas the bricks and tiles ensure natural climate control.

Sustainability in action: More than just an artistic object

The „Windfänger“ is an example par excellence for multifunctional architecture, and the sophisticated irrigation system is particularly convincing: At three spots, the sculpture is irrigated from above by a water supply system. Water is running over projections and recesses, similar to a play of water and is collected and filtered in water basins. Sensors control the system in such a way that it adapts to different daytimes, weather conditions and the sun, in order to use water efficiently. The evaporation is drawing heat from the environment, with creating a comfortably cool and humid atmosphere inside the sculpture.

„The cascading downward flow of water is somewhat splashing when hitting the protruding ‚monk and nun‘ tiles. The wind blowing through the sculpture is cooled in this way and, at the same time, carries the small water droplets along that we sense as pleasantly cool on the skin in summer,“ explains a representative of Breathe Earth Collective.

This evaporative cooling creates a comfortable micro climate and helps to reduce traffic noise and particulate matters – an added value that is not be underestimated at a crossroads with heavy traffic.

„The ‚Windfänger‘ sculpture at Europaplatz is synonymous with participation, deceleration and awareness of the climate crisis. It is a memory of the former fountain that decorated the Europaplatz square until 2023, and in conjunction to the new circular promenade it appears as the gateway to the traffic-calmed city center. My thanks do not only go to all parties involved in the project who brought this exceptional work of art to life, but also to all those people who perpetuated their names as part of it with their sponsorship demonstrating their solidarity with our city,“ states Mag. Matthias Stadler, the mayor of St. Pölten.

Complex concrete elements

The technical implementation of the „Windfänger“ sculpture placed highest demands on all parties involved. Rauter Fertigteilbau GmbH, a subsidiary of the Kirchdorfer Group, manufactured the complex concrete elements with highest precision.

Thomas Manessinger, project manager at Rauter, explains the technical challenge: „We have produced six precast elements of the gate frame, which were bent on two axes. Thanks to our outstanding possibilities in terms of formwork construction and technology, we were able to manage this demanding task successfully.“

An intensive process, because the six prefabricated elements of the iron arch resting on the gate frame were screwed among each other, positioned on the precast elements and poured with concrete on site. The assembly of the gate frames require a precise adherence to the measurement specifications regarding the circular shape and height to ensure the performance of the subsequent masonry works as planned. Wooden templates guaranteed an exact separation of the more than 40 m long perimeter. The second upper iron arch consisting of six precast elements was supported by columns initially, and then lowered to the last row of bricks as soon as the masonry works were completed.

It is also quite special that the citizens are incorporated in the project. 1,000 sand-colored bricks can be „acquired“ through sponsorship, by which the St. Pölten-based people can literally inscribe themselves in the work of art.

The „Windfänger“ in St. Pölten demonstrates impressively how modern concrete construction, traditional craftsmanship and forward-looking climate adaption strategies can merge harmoniously. It is not only a work of art, but also a vivid symbol for a sustainable and citizen-oriented urban development – a paragon that hopefully will find imitators in many other towns and cities.