Staircase G. is the first project to be realised using the Selective Paste Intrusion (SPI) method. As the central architectural element of a private house on Lake Garda, the staircase extends over two storeys and a total height of ten metres. The 3D-printed core of lost formworks allows the steps to cantilever from it, thus separating them from the surrounding interior walls and enabling a crucial separation for sound insulation.  

The load-bearing element of the staircase consists of 18 SPI-printed boxes that act as lost formwork. Weight optimisation to reduce the material used and assembly aids in the form of recesses for inserting the steel steps were already included during the planning stage. On the construction site, the steps were simply placed in the inserts provided in the respective formwork element. The individual elements together with the steps were then placed on top of each other, reinforced and cast at the same time.

This modular construction method allows for staircases to be installed in a short amount of time and offers many aesthetic and technical options for the design of the staircase and its separation from the surrounding building for enhanced sound insulation.

Scawo3D is located in the Sarentino Valley in South Tyrol and is one of the inventors and developers of the Selective Paste Intrusion (SPI) method for 3D concrete printing (3DCP). As the inventor and sole developer of print heads for cement paste, Scawo3D is at the forefront of large-format 3DCP.

The brand "Scawo" (Italian for "Scale Wohlgemuth", after the inventor and owner K. Wohlgemuth) originates from a patented technology for customizing concrete staircases from digitally designed and prefabricated CNC-milled EPS formworks. To continue meeting requirements for fire protection and current trends in the construction industry, Scawo3D started looking for ways to produce staircase formworks by 3D concrete printing, to ultimately build staircases from a single material only. By 2021, the SPI technology was successfully validated and a patent for the world's first print head for cement paste submitted.

Scawo3D and Skeno work together since 2022 and have completed multiple architectural and interior design projects. Since 2023, Skeno is partner in a R&D project for further developing the "Scawo" formworks, aiming at an optimization and automation of computational design workflows for 3D printed staircase formworks.