Wendeltreppe Stahl Epple

Sculptural steel spiral staircase

Dynamic elegance

The self-supporting steel spiral staircase runs from the atrium up three floors in the new building of Gustav Epple Bauunternehmung in Stuttgart.

Project description

Steel spiral staircase for traditional location

With a strong commitment to Stuttgart as its location and a novelty in construction technology, Gustav Epple Bauunternehmung GmbH realised its new three-storey headquarters with a monolithic construction of the outer wall using insulating concrete, and thus completely avoided the use of artificially produced insulating materials. The general contractor was founded in 1909 in Stuttgart-Degerloch as a small carpentry firm and is meanwhile represented throughout Germany. The company sets high standards for ambitious, creative and ecological building with the philosophy “Anders.Bauen” which means to build differently. Corresponding to the shape of the premises, the floor plan was designed as a slightly modified triangle. The puristic design with exposed concrete elements, wooden surfaces and a self-supporting steel spiral staircase dominates the interior of the building on approx. 4,300 sqm.

Sculptural dynamics

The working levels, created as an open-space concept, are arranged around the light-flooded atrium and are interconnected by a central spiral staircase made of steel. Far beyond its function as a connecting element, it fascinates with strong sculptural dynamics and corresponds to the open, clear architecture of the building. Rounded and constructed according to the triangular ceiling openings, the steel spiral staircase is a striking eye-catcher for both employees and visitors and, as a steel object, contrasts with the interior design concept of exposed concrete and wood panelling.

Freitragende Wendeltreppe aus Stahl
Image gallery
Project details

Steel spiral staircase

  • Self-supporting spiral staircase with both-sided, parapet-high flat-steel stringers as fall prevention
  • 2 staircase flights ground floor – 1st floor – 2nd floor; evenly rounded
  • Diameter inner/outer stringer approx. 2,320 mm / 5,320 mm
  • Stringer height approx. 1,490 mm, stringer thickness approx. 15 – 25 mm
  • Effective flight width approx. 1,500 mm
  • Intermediate landing and stair head landing each analogous to the spiral stairs’ flight

Step and landing construction of the spiral stairs

  • Steel plate steps in box-type design, 6 mm, bent upwards at the front and the rear, upper cover sheet flush welded, with mineral wool cavity insulation
  • Stainless steel stepping edge as edge protector, flush welded on top of the surface cover
  • Steel landings 1st/2nd floor analogous to the tread step construction, with additional transversal ribs consisting of double T-sections, closed with cover plate on the bottom –> box-type construction with smooth-faced soffit and varying opening angles according to the stairs’ flight

Handrail with light cove

  • Flat-steel construction on both sides of the steel spiral staircase, top side welded horizontally and projecting inwards to the balustrade stringers, 50 x 10 mm
  • Continuing on the landings of the steel spiral staircase
  • Extended to light cove with vertically welded flat steel, 40 x 10 mm
  • Visual closure on the stairs’ foot and head with vertical, rectangular hollow section; also serving as cable routing

Additional services for steel spiral staircase

  • CAD design and construction planning and comprehensive 3D detail views (axiometry) with freely selectable viewing angles for the steel staircase
  • Calculation and preparation of the verifiable structural analysis and a vibration verification for the steel spiral staircase

a+r Architekten GmbH Stuttgart