The spores produced by certain plant species give life to new organic structures and are adapted to achieve maximum results with minimal means. This is the principle behind the load-bearing structure of the Spore Initiative building. It was developed and realized, from design competition to construction, with the aim of providing a building envelope and flexible space that would be equal to its future use. Located in Berlin’s Neukölln district, this new public forum for cultural, environmental, and political cooperation and dialogue was to create a regional and international draw and become a center for the promotion of sustainable and empathetic coexistence.

The first challenge was to construct a foundation pit and footings within a confined space located amid various structures that had to be protected without compromising an adjacent brick-built underground railway tunnel. The museum space on the first floor and the ground-floor foyer, both column-free, were a major sticking point. Ultimately, the problems posed by these open-plan spaces on one hand and by the foundation issues on the other were resolved by a cleverly balanced system of pre-stressed wall panels spread over three stories.

The building, its prow-like corners overhanging the load-bearing cores by up to 12m, appears to hover above the ground. The cores themselves are subject to high stresses due to load concentration and therefore able to transfer horizontal forces efficiently. Despite the high concentrated loads exerted by the cantilever parts of the building, the carefully calculated distribution of loads into the reinforced concrete cellar walls made the choice of an advantageous raft foundation possible.

With its minimal use of materials, the Spore’s ceiling – the building’s key architectural element – gives the public space on the ground floor a distinctive identity that impresses long before you enter the building. Though the original competition entry featured a honeycomb structure with occasional supports that divided up the space, the difficulties encountered in specifying the foundations and the usage requirements meant that these columns were eventually removed and the structured ceiling redesigned. The final ribbed structure is the product of an iterative study and is based on the principal stress trajectories required for its membrane-like rigidity and bearing conditions.

The facade is monolithic on all sides, using a reddish recycled concrete at ground-floor level and recycled clinker bricks and new firebricks for the upper stories. The anchors conventionally used in masonry and in-situ cast concrete facades proved ill-suited to the project in terms of price and, more importantly, in light of its specific load and deformation requirements. As a result, it was necessary to develop a new, more efficient anchoring system in order to retain the monolithic appearance of the complex desired by both architects and client.