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A new renovation and extension to the Swiss Société Privée de Gérance (SPG) features a complex facade composed of four layers of glass. Designed by Italian firm Giovanni Vaccarini Architetti, the sophisticated building envelope offers a new aesthetic identity for the office headquarters while achieving energy efficiency.
- Facade Manufacturer
Giovanni Vaccarini Architetti; Fossati Architectes SA (Technical direction)
- Facade Installer
Metal Glass Sagl
- Facade Consultants
Stahlbau Pichler (facade consultant); BCS SA (facade engineer); SIMOS (facade lighting design); Wintsch&Cie (structural, electrical, and mechanical engineering)
- Date of Completion
double skin curtain wall
custom screen-printed glazing blades with aluminum attachments
The facade is composed of a double skin envelope, which allows the envelope to be naturally ventilated. A perimeter ventilation system paired with an interior forced air system reduces overall energy demands on the building by addressing thermal extremes at the facade. Vertically oriented glass fins treated with a frit coating are employed as a solar shading device. Stahlbau Pichler, the project’s facade consultant, worked with the architectural team to develop the enclosure system’s steel structural components which support the glass fins. The composition of glass and steel establishes a rhythmic composition that blurs light reflections, materiality, and the profile of the building.
The facade system relies on repetition to produce these complex aesthetic effects. In a press release, principal Giovanni Vaccarini said the team’s design process was inspired by weaving: “Weaving is the first step in composing… the weaving is a rhythm of signs, an abstraction of meanings, figures, and suggestions.”
Here, a triple-layer glazing assembly offers thermal protection, while the fourth layer of glazing is offset to establish a ventilated cavity space. Within the assembly, micro-perforated shading similar to Venetian blinds offer regulation of daylight. Outboard of the building envelope, the brise-soleil screens are composed of screenprinted glass. Stahlbau Pichler’s engineering helped to minimize visual distractions of the glass fin anchoring system. Their work also managed the 100-ton glass weight, a primary concern due to the structural constraints of the existing building.
The effect of the facade can also be experienced from the interior, where Vaccarini says the assembly produces what he called an augmented window. “From the outside, the ‘thick’ surface of the screenprinted glass panels and the steel become a volume and define the very body of the architecture, whose outlines dematerialize into a pulsating material entity sensitive to color changes in the surrounding area,” Vaccarini said. “Our perception of the building is continuously transformed. The overlapping visions we have of it, from both the inside and out, produce a kinetic effect.”
At night, the effect is intensified when glass panels and the edge profiles of custom-profiled aluminum anchors are lit by a bright white LED lighting system designed by SIMOS. This graphic further softens the perimeter surface of the building, producing what the architects call a visual reverberation effect.