The Order of the Sisters of Mercy of the Holy Cross has been based in Ingenbohl above Brunnen for over 170 years. Now the convent complex has been extended by the addition of a seven-story residential retirement and nursing home. Set on the eastern slope of the hill, it cleverly connects the lower level of the new visitor car park to the convent plateau. The new building comprises a roof-top plant and service level, six upper stories, a ground floor and four basement levels partially set back into the hillside. Its facades are structured by a grid of visible columns, floor and balcony slabs that traces the flow of forces through the structure. Two colonnades, on the eastern and western sides of the building, form a covered passageway and underline the significance of the building’s plinth. Stamped trass lime, a traditional, local material, was chosen as a sustainable alternative to the classic fair-faced concrete finish. The addition of lime and trass reduces the amount of cement used by half and so significantly improves CO2 balance.

The load-bearing structure is designed as a solid reinforced concrete skeleton with a bracing core. The floors take the form of point-supported flat slabs that offer high flexibility and generous span widths. Horizontal forces from wind and earthquake loads are transferred via the shear-resistant slabs into the reinforcing system of the core walls. The interior columns are arranged so as to run down into the foundations without bracing. This design is further strengthened by post-tensioning with subsequent bonding.

One of the architectural features of the new building is the integrated chapel. Located on the ground floor, it rises two stories to give an impressive ceiling height. Its design, complete with extensive glazing and stamped trass-lime walls, creates an air of spirituality. In the ground-floor foyer, where the walls are finished in the same stamped trass lime as the chapel, a triangular suspended steel staircase leads to the upper floors.