elliptical glass dome


primary steelwork


insulating glass

mansueto library

The Mansueto Library is Helmut Jahn’s up-to-date extension to the existing Regenstein Library in Chicago. Buried deep in the ground is a fully automatic high-bay archives section. Above that there is the new reading room with its vast ellipsoidal glass dome of nearly 2,800sqm.

Library users enter the new building, which is directly adjacent to the current library, via a glass-sided, glass-roofed bridge spanning almost 30m between supports. The structure to the elegant glass dome above the entrance level of the new building consists of a steel-and-aluminium framework. Elongated rhombuses form the primary structure – a total of 150t of steel.

  • The 1,200+ circular hollow sections have different wall thicknesses to suit different structural requirements. These sections are connected at various angles via 625 CNC-milled nodes. Located on top of the primary structure is the aluminium framework for the glazing, adjusted by means of steel pins. Each of the mainly trapezoidal insulating glass panes, almost 700 of them, is fixed with two black-painted point fixings on each edge. For the first time, a solar-control coating was applied directly to ceramic screen printing. From outside, the observer sees a pattern of black dots. Inside, on the library side, there is a congruent pattern of white dots. This is finished with the solar-control coating to the glass.

    Erection proceeded with pre-assembled segments, with extremely high torques being required for the connections because of the size of the dome. A digital design process throughout with generically parameterised planning reduced the number of operations and enabled a direct transition to automated fabrication processes.

    Images: © seele / Matthias Reithmeier


Client University of Chicago
Architect Murphy/Jahn Architects
Engineer Engelsmann Peters GmbH
Date of completion 2011
Scope of seele supply
  • Ellipsoid glass dome, approx. 73m long, 37m wide and 11m high
  • Connecting glass bridge

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