The project comprises the expansion by a fourth track of the current inner-urban station Zürich-Stadelhofen and an adjoining tunnel. It is designed in combination with the second single-tracked tunnel Riesbach between Zurich-Stadelhofen and Zürich-Tiefenbrunnen. The additional track will be connected by a tunnel link to Zürichberg Tunnel to increase flexibility.
The track will be built earth-side of the existing station partially by cut-and-cover but mainly by closed construction. Operation will be maintained during construction which takes place in a very constraint area.
As basis for future stages, the preliminary project (SIA-Phase 31) modelled the station building within the existing structures and their surroundings (incl. terrain, construction soil, supply lines and adjoining buildings). Moreover, the new construction elements were pre-modelled in a rough model for the architectural competition.