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The Insulated Glass Unit (IGU) has long been established as a transparent façade element offering improved thermal heat transmittance, often in conjunction with additional shading devices such as louvers or blinds. Minimizing the use of extraneous materials, this project focuses on enhancing the components and surfaces that are already part of a conventional IGU to achieve self-shading properties. One existing technology, glass slumping, already exists to create curvilinear, sculptural forms for a single layer of glass. When considered in conjunction with other existing glass treatments such as surface etching or ceramic frit patterns, slumped glass has the potential to perform as a visually dynamic and environmentally responsive part of an IGU, improving the shading of direct light while presenting imaginative forms to a building’s exterior.

SSIGU Makeup

The proposed triple-glazed, structural IGU is comprised of a slumped outer lite with an opacity zone on the number 2 surface, an intermediate float glass lite, and a structural laminated fully tempered inner lite with ionoplast interlayer.

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The Parametric Analysis Setup

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Implementing emerging computational tools and collaborative workflows, the design team directed a feedback loop that linked form, material and environmental performance for a specific site. Within a reasonable computer runtime, the parametric modeling tool Grasshopper, its integrated optimization plug-in Galapagos, and the environmental analysis plug-in Diva were combined to generate closely calibrated solutions that address desired daylight and solar performance.

To model the complexity of the proposed design, the proposed slump panel was set up with seven variables: slump amplitude, slump frequency, slump height, shading density, an opacity value and attractor splines to control programmatic influence. Each of these variables is controlled by a simulated annealing algorithm in Grasshopper’s optimization tool Galapagos with the goal to find an optimized combination between Useful Daylight Index (UDI) and solar radiation to balance the need for shading in the summer, heating in the winter, and day lighting.

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Based on the results of this optimization, appropriate designs were adopted. The attractor splines are controlled by the designer to define glazing areas in need for particular transparency, and fed into the optimization procedure.


In a constantly advancing fabrication landscape, our proposal aims at reaching new limits with glass slumping technology. Today, few methods exist for creating a slumped panel with slump depths necessary to create a highly varied curvature. To challenge potential fabrication limits, we conceived of a slumping method that utilizes an adaptable ceramic bed and a set of coils whose activation and temperature outputs can be digitally controlled to accommodate an infinite set of slump profiles.