Façade specialist seele constructed the museum of westward expansion and visitor center right next to the Gateway Arch in St. Louis, USA.


structural steelwork


bent façade panes with



high-tech glass structure for a national monument: jefferson national expansion memorial visitor center

The world-famous Jefferson National Expansion Memorial in St. Louis was built between 1961 and 1965 and features the 192m high Gateway Arch. Plans for an architectural upgrade to the area around the monument have existed since 2007. The implementation of those plans began in the subsequent years and included the complete redesign of the park and the entrance zone.

As part of these measures, seele was appointed to design and build a spectacular new entrance to the visitor centre and museum. The seele design consists of a 5.5m high glass façade with bent glass panes and a glass roof.

  • The roof comprises a total of 74 three-ply laminated panes in sizes of up to 5.5 x 2m which are supported on a steel structure weighing 85t in total. The 38 stainless steel cantilever beams are made from milled solid stainless steel sections tensioned with tie bars and fabricated in seele’s own plant in Plzeň. A pattern printed on the glass lends the roof glazing a feeling of vitality, but also regulates the transmittance of light and heat.

    The largest of the 24 panes making up the façade measures 1.4 x 5.5m and each pane weighs 460kg. The joint between façade and glass roof permits movement. From inside the building, the uninterrupted glass façade permits spectacular views of the area in front of the Jefferson National Expansion Memorial and also the city skyline.

    seele initially built a mock-up of the proposed solution on its own testing grounds in Gersthofen. The mock-up consisted of three cantilever beams and the roof panes mounted on these plus the bent façade panes, and this was presented to the architect and the client as the result of the planning work.

    Reference overview and Header image: © Nic Lehoux

With a height of 192m, the Gateway Arch at Jefferson National Expansion Memorial soars above the banks of the Mississippi. © Nic Lehoux
The appendant museum, opened in 1976, portrays the history of the American West in the 19th century. A new entrance area for the visitor center and museum complements the building. © Nic Lehoux
The new entrance façade with panes up to 5.5m ensures maximum transparency and a great view of the courtyard. © Nic Lehoux
View from the inside of the museum to the park area. © Nic Lehoux
The milled stainless steel solid profiles form the supporting structure for a total of 74 triple laminated roof panes.
In summer 2016, seele built a visual mock-up consisting of two façade panes, steel cantilevers and the corresponding roof glazing.

Project diary

Installation progress at Museum of Westward Expansion

Since February 2017, installation of the steel-glass-structure for the new entrance area of the Museum of Westward Expansion in St. Louis, USA, was carried out. After all 38 stainless steel cantilevers had been installed, glazing works started.

  • 29/04/2018
  • 24/08/2017
  • 28/06/2017
  • 28/06/2017
  • 14/06/2017
  • 31/05/2017
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Short before the official opening. © Kevin Brookes


Installation is in the final spurt. Steel and glazing works are completed and now sealing works follow. © CityArchRiver/Earthcam


View from the Gateway Arch down to the museum and the nearby Old Court House.


The glass installation is in full swing and also glazing works of the lobby façade has started.


The glass installation of façade and roof has begun.


24 of 38 stainless steel cantilevers - up to 8m Long - have already been installed and aligned.


Client United States Department of Interiors National Park Service
Main contractor McCarthy Building Companies
Architect James Carpenter Design Associates | Cooper, Robertson and Partners
Engineer Alper Audi Inc., EOC
Date of completion 2018
Scope of work by seele
  • Glass roof with 74 panes in sizes of up to 5.5 x 2m and their supporting cantilever beams
  • 24 bent panes for façade, each weighing 460 kg and measuring 4.2 x 1.4m
  • 85t structural steelwork (seele pilsen)
  • AL Design Awards 2019
  • AIA St. Louis Design Awards 2018
  • LEED Gold Certificate 2019