Soaring barrel-vaulted glass roof graces Philadelphia's new Kimmer Center for the Performing Arts

The barrel vault ends on both sides in two colossal glass arches; both 'end walls' are also made of laminated glass with Butacite©.

The self-supporting barrel vault of laminated glass is unique for its huge size (radius: 26.5 m; span: 53 m; total area: 12,000 m2) and for its striking and varied aesthetic since it appears to float above the two transparent end walls. Project Architect at Rafael Vinoly Architects, Charles Blomberg, told LGN: "We were inspired by the great winter garden or greenhouse architectural structures of the nineteenth century, like Crystal Palace in London. The lobby is important at the Kimmel Centre; it is a place where people can gather all day and into the night in all weathers, year-round."

The Kimmel Center's roof is based on a column-free, self-supporting, 53 meter Vierendeel truss to arch across the span, and on folded glass plate action to create longitudinal stiffness. Blomberg explained: "There are no square or triangular panels of glass. Instead, the glass panels are leaning against each other at an angle of 45 degrees. The membrane of the arch therefore resembles a folded plate structure when seen close up and achieves the structural rigidity we needed; it's like window mullions holding up the building! The result is a pure, gravity-loaded arch of laminated glass that can bear snow- and wind-loads."