Unlike the spiral staircase, which wraps around a central column, the helical staircase is a structurally independent curved form — a continuous sweep in space that requires no central support and generates one of the most complex engineering challenges in bespoke fabrication. Siller Treppen has built its international reputation in large part on helical staircase commissions, where the form becomes the architectural centrepiece of a space: a sculptural gesture that choreographs movement while defining the spatial hierarchy of the interior.
The engineering of a helical staircase begins with a precise structural model, as the form must be self-supporting across its full arc. Siller achieves this through a combination of internal steel substructure, custom-welded spine profiles, and tread-by-tread load analysis. The visible material language — whether timber veneer cladding, polished concrete, folded steel, or glass — is applied over this structural skeleton, allowing the finished staircase to read as monolithic while concealing the complexity of its construction. Every helical stair is site-measured, workshop-built in sections, and installed by Siller's own team to guarantee fit and finish.
Helical staircases by Siller are found in some of the world's most architecturally distinguished private residences, luxury hospitality projects, and cultural buildings. They are the stair of choice when architects seek a circulation element that transcends function and becomes a spatial event — a design decision that defines the character of an entire interior.
