This project focuses on slag, the anthropogenic end product of waste incineration. In Hamburg alone, around 170,000 tons are produced each year, about half of which is deposited in salt mines. Slag thus marks the end of an urban material cycle. The design begins precisely at this point: it makes the mass visible while simultaneously investigating the spatial and constructive qualities of the material. 

The starting point is the temporary situation of Kampnagel (cultural production space located in Hamburg), which requires alternative venues across the city during a five-year renovation phase. The project understands this necessity as an opportunity to develop new performative spaces while contributing architecturally to the societal discourse on consumption and its residues. The chosen site is the former Esso-Häuser on the Reeperbahn, which has remained unused since its demolition in 2014. Here, slag is heaped up and shaped into a transformable topography that serves as an accessible and performative landscape. Within this mass, the necessary spaces for performances are embedded along the former foundation structures. 

The spaces emerge directly from the material itself: slag is contained between inner and outer layers of expanded metal and stabilised using wall anchors. An additional steel structure absorbs the lateral pressure forces. Above, a textile roof spans the space, providing flexible coverage for performances. Steel plates beneath the slag act as temporary foundations, enabling a reversible construction. The design transforms slag from an invisible residual material into a defining architectural element, making the material consequences of urban life immediately tangible.