APARTMENT BUILDING WITH TRANSFER TRUSS, LATSIA

From the street, the building seems to rest on a lattice of white diagonals. Behind that lightness, the loads of four floors reach the foundation at just two points, 1.70 m apart.

Andreas Marcou designed this residential building in Latsia for CYview, with an open ground floor for parking, a mezzanine, three floors of apartments and a fourth floor of storage and ancillary rooms. The diagonals that define its street front are not decoration. They are the structure that carries the building.

We engineered them as a reinforced concrete load path. The four (4) floors above rest on a 9 m truss (Truss-1), and on three of them the floor slab cantilevers 2.55 m beyond the line of the truss. Truss-1 sits on a second, 5 m truss (Truss-2), and Truss-2 stands on four raking columns. The columns meet in pairs, so the entire superstructure arrives at the foundation through two points carrying 1,845 kN under service loads.

Our structural analysis and design focused on what that concentration means. Because the columns are inclined, they carry horizontal forces as well as vertical loads. Because the trusses are stiff, the structure is highly sensitive to settlement: a small differential movement would redistribute forces through both trusses and could crack the floors above. The foundation is therefore designed as a single raft across the full 10 × 18 m footprint, around the ground's settlement behaviour, not only its bearing capacity.

The result is a building where the most visible architectural element is also its primary structure.