A multinational Building Team responsible for remaking the dilapidated headquarters of Argentina's premier daily newspaper into a Class A office tower had to execute the $30 million expansion in the heat of a charged political and economic climate and without disruption to the newspaper's quotidian operations.
The ambitious plan involved construction of a 16-story steel-framed structure atop the 1950s six-story, concrete-frame podium that housed the offices and printing plant of La NaciĂłn, Argentina's national newspaper. With its breathtaking location along the Rio de la Plata, the estuary formed by the convergence of the Uruguay and Parana Rivers that separates Argentina and Uruguay, the old structure was ripe for redevelopment as the new millennium began.
But before it could be completed, the project would sustain numerous delays and complications stemming from Argentina's brutal economic recession. Despite numerous setbacks, the project, developed by Buenos Aires-based RED Real Estate Developers on behalf of the newspaper, reached a successful conclusion in early 2004.
Plagued by more than a decade of growing international debt and devalued currency, Argentina's economy hit bottom in late 2001, in the midst of the addition's construction, when the unemployment rate swelled to more than 20%, inciting nationwide riots and demonstrations calling for President Fernando De la Rua's resignation. De la Rua finally quit his office in December 2001 following a spate of protests and riots that resulted in 28 deaths. Days later, the country defaulted on $155 billion in foreign debt payments—the largest such default in its history.
"The recession effectively shut the country down for a few years," says Ripley Rasmus, AIA, SVP and design principal with Hellmuth, Obata + Kassabaum, St. Louis, the project's design architect. "Banks were in such a terrible state that you could not draw out large amounts of cash to pay people."
This forced design-builder Techint CompañĂa TĂ©chnica International to "meter" construction based on the amount of money that could be drawn from the banks. Acquisition of materials and products was extremely slow, especially for imports like steel and glass.
Where possible, the local architect of record, Estudio Aisenson, substituted imports for local materials to reduce expenses and save time. These included exterior metallic profiles, ceiling panels, and lighting systems, according to Pablo Pschepiurca, partner with Estudio Aisenson.
Steel, the most costly import, could not be substituted for. "We needed to build lightly," says Rasmus. Specifying a concrete frame would have eased financial and schedule pressures, as local trades were working for next to nothing in the horrid financial climate. But the added weight of a concrete structure would have required substantial structural reinforcement to the existing podium structure, inflating the cost and making it virtually impossible for the newspaper to function during construction.
New York-based structural engineer Thornton-Tomasetti devised a plan that minimized structural modifications by utilizing the reserve structural capacity of the existing concrete frame. The building was originally designed to accommodate a three-story addition that was never built, as well as the newspaper's printing presses, which were moved to a suburban location before the project got started. Thus, the concrete frame was capable of handling about 10 times the magnitude of a typical office floor load, says Rasmus.
A 12-foot-high steel transfer truss system located on top of the base structure distributes the column loads from the steel-framed addition to the concrete columns below. Designed by Thornton-Tomasetti SVP Udom Hungspruke, the truss was fine-tuned to divide loads based on the strength available in each individual existing column. This approach limited column strengthening and accommodated the differing column grids of the old and new structures. (The steel-framed addition features larger bays and requires fewer columns than the existing concrete structure.)
The concrete core of the existing building, deemed structurally sound by engineers, was extended the full height of the building to provide sufficient lateral stiffness for the addition to resist wind loads.
To keep disruption of the newspaper's day-to-day operations to a minimum, the team revised the structural plans for reinforcement work on the busiest floors (levels 3–5). Columns that required reinforcement were strengthened with steel plates, which they deemed a faster, cleaner, and quieter method than cast-in-place concrete reinforcement. More obtrusive tasks, such as transforming the foundation's 20-inch-thick reinforced concrete mat to an 80-inch-thick post-tensioned slab, were scheduled after hours at the newspaper, from 2:00 a.m. to 8:00 a.m.
Before construction work could begin, utilities and building systems located on the roof of the original structure—cooling towers, piping, ventilation shafts, and electrical infrastructure—had to be relocated to ensure that the office would remain fully functional, according to Alejandra Rabuffetti, architecture design manager with Techint.
Rabuffetti says a few of La Nacion's more inquisitive journalists working in the building expressed doubt about the scope of the project. "Some were very worried, especially during the structural reinforcement phase when they saw that some columns on their floor required reinforcement," says Rabuffetti. "They asked how the building was going to bear the load of the new tower. We did our best to calm them."
A breath of fresh air
The building's distinctive shape is a direct response to the city's setback restrictions, which were designed to protect existing buildings from being denied daylight and views by the flurry of new construction in the city. The east façade bends backward at a 10-degree arc beginning at eighth level, effectively "doing the limbo" just a few feet beneath the maximum-height tangent line. Its north and south façades step back five to 10 feet at levels 8, 15, 19, and 23 on the north face and at levels 11, 17, 20, and 24 on the south face to squeeze within the pyramid-shaped setback restriction area. Its west façade steps back in a similar fashion, but with much less severity.
Outdoor terraces are introduced at each setback. "Buenos Aires means 'good air,'" says Rasmus. "And for a good portion of the year, you can sit on the terraces comfortably."
The 16-story addition is composed of two towers linked by the concrete circulation core. Each tower has its own view and its own personality. "One is a river building, the other is a city structure," says Rasmus.
The curving east tower provides magnificent views of the Rio de la Plata and features large, deep floor plates about 11,800 sf in size. These "American-style" offices, with their sizable, open plans, are geared toward attracting large U.S.-based companies, such as financial and consulting firms, wishing to establish satellite offices in Buenos Aires to serve South America. The smaller, upright west tower (5,300-sf floor plates) faces a treed plaza and surrounding office structures, creating a more urban experience.
This design approach gives the client flexibility "to market each floor as two unique addresses, each with very unique qualities," or to join the east and west floor plates to offer a unified space to a single tenant.
The strategy seems to be working. Much of the 394,000 square feet of office space is leased, despite a stagnant local office market. La NaciĂłn occupies three floors in the original podium structure, while PricewaterhouseCoopers, the building's largest tenant, leases five floors across the east and west towers. Norwegian telecommunications giant Nortel occupies the 17th floor, and the project's design-builder Techint recently moved its headquarters into six floors.
