The Princeton Envelope Group (PEG) is a design and research unit at the Princeton University School of Architecture. Headed by Alejandro Zaera-Polo and coordinated by Urtzi Grau. The unit is engaged in a three year research program on the Politics of the Building Envelope the conclusions of which will be published in a forthcoming book by Actar Press, Barcelona+New York.

Repetition and Difference

Architecture has been used often as a mechanism to exercise biopolitics, as a technology that enables the subjugation of bodies and the control of populations. The envelope is the first mechanism to produce a physical control of a population as it delimits the space in which a population is contained, and serves as a filter to determine the qualities of the population and its degree of isolation or permeability. It sharpens or dissolves the limits between populations. The envelope is also the primary representation of a community of inhabitants. From it, a community decides whether to present itself as differentiated or as homogeneous, and the type of subdivision of the building units in a building’s envelope.
A population is usually the repetition of a type of individual or cell, but the modality of this repetition is crucial to the nature of the organization. Modular societies tend to be more egalitarian but also contribute to erase variation and difference. Whether an envelope is designed with a modular pattern or with a centralized pattern may have a decisive effect on the configuration of the enclosed space and the politics of the community that inhabits it. The variations between a repetitive modularization and a differentiated one are important mechanisms to the political structuring of space and the representation of the community.
The tessellation system of an envelope bears crucial importance in determining its environmental performances. There are uniform and non-uniform, periodic, quasi-periodic or non-periodic tiling; variable tessellations, like the ones included in the wallpaper group, and non-uniform tessellations like Voronoi tessellation and Delaunay triangulation. Depending on the type of tessellation and its relationship with the overall volume we many reduce the numer of vortexes or the length of joint. There is a possible history of the joints in construction (overlap, abutt, spaced, standing seam, siliconed, mortor, etc) that relate to tolerances, waterproofing, drainage, use of sealants or mortars, load transfer and mechanical restraint (like in the dovels of an arch or in the unitized tiles of a curtain wall) and iconographic performance. The quality of the edges and articulations between the tiles are crucial to the permeability of the envelope in environmental, visual, or physical terms.