ALCOA CORPORATE CENTER, Pittsburgh, Pennsylvania 1994 - 1998.

-- Building Description :  

The new ALCOA World Headquarters Building

The construction of a new corporate headquarters, known as the Alcoa Corporate Center, has now been completed. This new generation of office building supersedes the noted Harrison Abramovitz's 1953 Alcoa Building, a slender thirty-one story office tower clad in stamped aluminum panels, as the new world headquarters for the Aluminum Company of America (ALCOA).

The new building is located in North Shore, a waterfront site across the river from downtown Pittsburgh, Pennsylvania, part of regeneration of urban industrial sites in the city. It is a six-story office building (236,200 sq.ft./ 21,300 m2) plus an underground garage (96,000 sq.ft./ 8,600 m2). The building is to house a concentration of the company's corporate-core for maximum proximity and collaboration. The organization of the new building is a clear departure from the old headquarters, reflecting corporate changes in ALCOA's workplace thinking.

o f f i c e   f l o o r s

Office floor plates are large (29,000 sq.ft./ 2,600 m2 net usable), contiguous, and uninterrupted by any vertical shafts or other permanent fixtures. All service cores stand outside the office floors -- allowing a stacking of long span (60 ft./ 20 m. between columns) unencumbered loft spaces (each measured approx. 300 ft./ 100 m by 90 ft./ 30 m), to be used primarily as flexible open offices.

For greater working comfort in such expanse of space, natural daylight penetration to the workplace -- as well as views to the river and downtown skyline -- are optimized by providing an exceptionally generous ceiling height (11 ft. 6 in./ 3.5 m.; floor-to-floor height is 15 ft. 10 in./ 4.8 m.) and by utilizing the total transparency of the non-reflective -- "colorless" -- ultra-clear (low-E) glass. (PPG's low iron oxide water-white "Starphire" glass).

All building's vertical surfaces are bared to their metal skeletons, allowing nature and "urbanity" -- congested forms of irreconcilable types and sizes -- to permeate deep inside the interior of the building, into the equally wall-less landscape of open, flexible workstations. Sense of openness and exposure are further heightened by deep perimeter cantilevers (15 ft./ 3 m. all around the office block) and the absence of all corner columns in the building.

To temper -- and indeed to maximize -- the relentless dimensions of the office floors, the footprint of these plates is "modulated" in its length, echoing geometries of the three identical catenary bridges framing the site. (All curvature of the building is of one radius only.)

These large, light and airy, open generic floor spaces of undetermined interiors are serviced by the single-sided external / perimeter cores on the north side of the building. Air, electric, and telecommunication cables are fed to the office through a raised plenum-floor system -- the false modular floor providing flexible cabling arrangement and efficient air distribution for a very high-ceiling environment.

b u i l d i n g   o r g a n i z a t i o n

The building is planned -- its spaces and components are "arranged" -- to intensify the creative-productive aspects of corporate work: "consolidation / condensation," "juxtaposition / (over)exposure," "distraction / communication," "visibility / teamwork," "transparency / fluidity," "casual encounter / random chances" of everyday working. Building arrangement seeks to unleash a workspace that is informal, adaptable, accessible, and catalytic -- i.e. conducive to office interactions, an active agent for unpredictable changes in business processes.

The overall organization of the building is straightforward, utilitarian, and clearly expressed. It is an unmediated layering of distinct -- elemental -- linear volumes: the serpentine block, the thin vertical-slab, and the skyline-silhouette. This parallel alignment of three buildings -- the "three extrusions" -- occurs along and within, hence further emphasized, the parallel alignments of the river-edge landscape, the site of the building.

From south-to-north, the linear volumes / buildings / landscape -- all parallel to the water/ river-edge:  

• northern edge of downtown (strips of riverside boulevard/ highway and promenade)
• the Allegheny River, US Corp of Engineers 'flood line'
• Alcoa's waterfront terraces
• the serpentine block, the floating boulder, the pristine glass prism, the S-office lofts
• the glass-wedge, the voided beacon, the lightwell/ atrium, filled with cascading escalators
• the thin vertical-slab, the "core-building," the circulation-bar, the external service core, the thin "wood-wall" structure, the slim orthogonal-bar building.
• the skyline-silhouette -- an "urban" profile of linear blind-walled buildings housing mechanical penthouse, service tower, sidewalk restaurant, and entrance pavilion
• existing 19th century cobble-stone paved Isabella Street

p u b l i c   a c c e s s   &   a m e n i t i e s

Outside the building, layers of linear "urban orchards" -- rows of precisely aligned "geometric" trees and low stone walls -- connect the public to the water. (Trees and plants are native and water-based). Parallel strips of level and reclining surfaces provide a gentle descent from the surrounding streets and bridges to the river, further clarifying the building's organizational strategy.

These strips stage a sequence of distinct waterfront experiences: overlooking, looking down, viewing across, strolling along, even (in the initial scheme) dipping one's toe into the water, at the stone-paved "beach" -- the water-level point of the river's continuous bicycle track, the city-wide "Heritage Trail".

These are the public accesses to the waterfront: the strolling footpath, the jogging lane, the push-bike trail, the riverwalk, the belvedere etc. In addition, on Isabella Street side of the building is a tree-lined sidewalk along the skyline-silhouette with a newstand, public restaurant, and the entrance to the building. The original cobble-stone paving of Isabella Street is restored and preserved, to remain as an urban "survivor" -- a strip from the last century.

e n v i r o n m e n t a l   f i l t e r

The clarity of the organizational strategy is enhanced by the juxtaposition of the different skins of the distinct volumes of the building. The serpentine block volume is wrapped by a patterned "glass-paper" into one pristine extruded prism. The vertical circulation-slab/ orthogonal-bar volume is sheathed on the exterior by frosted and translucent glass, and on the interior by wood panels, wrapped around that the whole bar-volume appears to be entirely "made of" wood in all its eight-story height and 27 ft./ 8 m width. The skyline-silhouette volume is clad in precision metal jacket of aluminum panels, with horizontal slot openings covered in fritted glass.

The curtain-wall consists of "unitized" frames of (5 ft./ 1.5 m) straight facet glass modules, with self-vented shadow-boxes and fixed external sunshades (with operable internal clerestory louvers/ mini light-shelves). These wall filigrees are all constructed of aluminum, as is the horizontal panel cladding of "blind-walls" of the service tower and mechanical pavilion along Isabella Street on the north.
(For descriptions on building enclosure, see "curtainwall" -- the non-hierarchical skin; the floating boulder -- serpentine block, the checker-skin wrap etc. in the folowing pages.)

c i r c u l a t i o n

Also clearly expressed is the interstitial, "left-over" space between the juxtaposing volumes. This "fourth (non-)building" is a linear void, a vertical slot of space wedged in-between the serpentine block and the thin circulation-slab / core-building. It is the circulation lightwell, the vertical "main street" of the building. This wedge of space is capped in glass, enclosing a "courtyard" -- not quite an "atrium," since the exterior wall of the serpentine block continues inside the building, albeit more porous -- filled in with (fun-)"rides": bridges and other machines of circulations.

These machines -- escalators (primary means of vertical circulation) and elevators, the moving parts of the building -- are sheathed in clear glass, exposing the mechanics of their machinery inside. They are fragile, transparent, and kinetic -- further inducing motion, dynamism, as well as plain sightlines and daylight to their riders -- fostering casual contacts, impromptu meetings in their daily floor-to-floor travel.

The glass-wedge is the tallest structure of the building. This "non-building" (the least programmed part of the building) is literally the beacon of the building, highlighting what is important, the mundane but most significant activities inside the building: free-fall circulation - free-flow communication, i.e. human interactions in all its improvisations.

i n t e r . a c t i o n

Each day inhabitants of the building penetrate the building layers as they progress from the street to their workplace (and the river, the distance downtown, and so on), teasing out precipitous potentials of the "layering": the effectiveness of proximity and "density"; the contagiousness of adjacency, contiguity, and juxtaposition. They climb the building, from the solid river bedrocks in the garage to the high, deep, light and airy workplaces in daily grand tour through indeterminate, transparent office-scape by the soaring chamber of exposed circulation open to the sky.

Aspirations of improving productivity, efficiency (hence business' "bottom line"), and the general well being in the workplace is served by natural and personalized comfort, ubiquitous information-technologies, openness, accessibility, and flexibility afforded by the building. The incessant frictions and exposure promoted by the architectural arrangement forever assures frequent casual encounters, direct open exchanges, and hence, sharing of ideas among building users.

© 1996, 1997 Agus Rusli

Rusli Associates, Architectural Design Consultant / Design Principal
The Design Alliance Pittsburgh, Prime Contract/ Architects of Record

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