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.

Flat Vertical

The category of the flat-vertical envelope, better known as a slab, includes those envelopes whose predominant dimensions are parallel to gravity and distributed along a line. Flat-vertical envelopes are generated by the horizontal displacement of a section of space, which, in order to support a specific function, optimizes density, daylight, ventilation, structural constraints, and the building’s relationship with public and infrastructure. Land uses and orientation are crucial drivers for this envelope type. Most mid-rise residential and many office buildings fall into this category, as they respond to the need to host a large volume of homogeneous program. The flat-vertical envelope is primarily determined by the facade-to-facade or facade-to-core depth, hence its laminar organization. Modern urban fabrics are predominately matrices of flat-vertical envelopes combined in various configurations suited to a particular climate, use, and culture. The flat-vertical envelope usually has a high level of environmental performance and a relatively low level of expressive performance.