Shearing Layers: How Buildings Learn, and What They Can Teach Us
In 1994, Stewart Brand published How Buildings Learn: What Happens After They’re Built, in which he confronted the illusion that architecture is permanent with the fact that buildings are always changing. Building on the work of British architect Frank Duffy, Brand proposed a theory of “shearing layers” — site, structure, skin, services, space plan, and stuff — to explain this process of change. In doing so, Brand challenged architects, construction professionals, clients, and inhabitants everywhere to reflect on how we might approach decisions about buildings considering all the ways a space might perform over time.
Shearing layers are evident at the University of Pittsburgh’s Barco Law Building in Pittsburgh’s Oakland neighborhood, which houses the law library, moot courtroom, classrooms, and administrative offices of the School of Law. The building was erected on part of the site of Forbes Field, the former baseball stadium and home of the Pittsburgh Pirates from 1909 to 1970. The law building was dedicated on May 1, 1976 and now shares the Forbes Field site with the University of Pittsburgh’s Hillman Library, Lawrence Hall, and Posvar Hall.
Barco is a component in a labyrinth of structural connections between Lawrence Hall and Posvar Hall. Stairs, columns, courtyards, covered passages, and pedestrian bridges link the buildings and form a maze of angles, reflections, and apertures.
Barco has six rectangular stories that stack atop one another and contain more boxes inside. Curiously, the law library’s fourth and fifth floors introduce round elements in the space plan through curving walls, overhead lighting, and reference desk furniture. The mismatch of geometries speaks to a space plan renovation that feels tacked-on and jarring: an unwelcome interruption to an ordered grid.
Barco’s concrete and dark glass skin is simple and unadorned, yet visually massive. It presents the study of law as a formidable and serious undertaking. The utilitarian quality of concrete is evident in the building’s services, which make no attempts to shield themselves from view on the exterior and interior of the building. They appear to have accrued over time, with older services existing alongside newer counterparts. Utility closets stand open just feet from sparse display cases that proclaim the ethos of the institution. Most of the stuff in the building is library and reference material; these are the interior spaces that feel fullest and most dwelled-in.
Concrete provides structural connections and visual continuity on the site of the Barco Law Building much like it serves as connective tissue for the Interstate Highway System, a 35-year public works project authorized by President Dwight D. Eisenhower in 1956. A comparison of the Barco Law Building and the Interstate Highway System demonstrates that beyond similarities in building materials lie conceptual linkages between the law, public space, and structural inequality.
Today, the site of the highway system is both national and local, as states own and operate the Interstates. It is currently 46,876 miles long and cost the federal government $129.9 billion (nine tenths of the total cost) to create. Its structure — roads, ramps, bridges, columns, piles, interchanges, and more — comprises one of the signature infrastructure projects in American history. Similarly to the Barco Law Building, its skin is concrete and asphalt. The services entailed in its design and maintenance include drainage, signage, plowing, and resurfacing, as well as law enforcement, military, construction, and toll workers. Its space plan enables the circulation of people, motor vehicles, and goods — the stuff.
Between the physical design of the highway system and the American people lie a complex set of shearing layers that speak to the consequences of design and how it has changed over time. On the one hand, the Interstate Highway System brought increased mobility and connectedness to a nation. It facilitated independence and autonomy while creating jobs all over the country. It contributed to improving safety of traveling in motor vehicles and was created in part to more easily move troops and military equipment from one area of the country to another. It continues to drive the American economy as goods travel on Interstates around the country.
However, its sites have contributed to the destruction of communities and structural inequality, while its skin and services have accelerated environmental degradation. In a recent article in The New York Times, author Kevin Kruse describes how Interstate highways were tools of segregation, often planning routes through “blighted” neighborhoods housing racial minorities and separating black and white communities. Instances of Interstates used as a method of segregation were not just confined to the American south, but were also present in cities like Chicago, Cincinatti, Los Angeles, Pittsburgh, and more. The U.S. Department of Transportation acknowledges the relationship between segregation and the Interstates; its website cites a study of the Interstate system and its relationship with cities by Professor Raymond Mohl, who described examples of local officials “routing an interstate through an inner-city community of African-Americans, wiping out housing in another along with the cultural and commercial heart of the community.” Meanwhile, the American transportation industry contributed 29% of greenhouse gas emissions in 2017, higher than the electricity, industry, commercial, residential, and agricultural sectors.
Peeling back the shearing layers beneath a tangle of concrete and steel reveals that infrastructure and its construction can be tools of violence and progress in the same stroke. It is unlikely that the architects and administrators responsible for constructing the Barco Law Building in relation to Posvar Hall intended to create “overbearing, cold-feeling buildings with barren plazas between them.” One could imagine that the purpose of such an interconnected structure and space plan was instead to facilitate circulation of people and ideas in the pursuit of learning and scholarship. More seriously, and on a much larger scale, the Interstate Highway System has ensured the mobility and economic futures of many Americans while forcing other communities and the planet to adapt (or fail) accordingly. When confronted with such a legacy, we might borrow from Stewart Brand. It is more important than ever to relentlessly pursue the imagining of possible futures — scenario planning, rather than programming — with as many different imaginations as possible. Architecture provides a useful, tangible lens for studying actions and consequences: who decides, and on what scenarios, remains a central provocation for the American democratic project.
