Hearst Tower: The Diagrid Diamond Revitalizing Manhattan

Series: Avant-Garde Constructions

Masterpieces of Architecture and Engineering: #04 Hearst Tower, New York

Editions: English Español Deutsch Français Italiano Português

How do you build a glass colossus upon a stone pedestal left orphaned by the Great Depression?

In 1928, Joseph Urban completed the construction of the Art Deco base for the Hearst Corporation headquarters. Although this six-story building was originally engineered to support a skyscraper, the economic circumstances of the 1929 Great Depression prevented the completion of the projected tower. Eighty years later, Norman Foster and WSP Cantor Seinuk not only fulfilled that dream but did so by breaking a sacred rule of architecture: they eliminated vertical perimeter columns.

Giant Surgery: Megacolumns vs. Art Deco

Following the wounds of 9/11, New York didn’t just need another building; it needed a manifesto of resilience. The Hearst Tower represents extreme urban surgery: the heart of the original monument was hollowed out, leaving only a six-story historical "shell."

To prevent the new tower from crushing the past, high-strength steel megacolumns were inserted, piercing the ancient base like surgical needles. The result is a colossal atrium where the tower appears to levitate above a 25-meter-high structural void.

The best architecture comes from a synthesis of all the elements that compose a building: the structure that supports it, the services that allow it to work, and the ecology of the building.

— Norman Foster

The "Diagrid": The Absolute Geometry of the Triangle

Forget the traditional orthogonal grid. The Hearst Tower relies on absolute triangulation. This diamond-shaped exoskeleton, known as Diagrid, is not an aesthetic whim; it is the purest form of physical efficiency:

The Triangle is Non-Deformable: While a rectangular frame deforms under lateral wind pressure, the triangle locks. This provides the tower with a torsional rigidity that a conventional skyscraper could only dream of.

Radical Material Saving: By allowing the diagonals to carry the full load (both gravity and wind), corner columns were eliminated. The result: 2,000 tons of steel saved (20% less than a standard building).

Uncluttered Views: With no perimeter pillars, the office floor plates are open fields. The steel does not block the view; it frames it.

The reliability and precision of the diagrid system in the Hearst Tower can be compared to that of a Swiss watch; my work has always been about stretching the horizon.

— Ysrael Seinuk, Structural Engineer (WSP Cantor Seinuk).

The Transfer Platform: The Gordian Knot

The most critical point of this engineering feat occurs on the seventh floor. Here, the Diagrid terminates and must transfer thousands of tons of diagonal loads into the vertical megacolumns that lead to the foundation.

A massive transfer platform was designed—invisible to the human eye, but vital for the building's structural integrity. It is at this junction where the physics of the diamonds yield to gravity, channeling forces into the ground without ever touching the 1928 historic facade.

"Icefall": The Water-Driven Lung

In a conventional skyscraper, HVAC systems face a losing battle against solar gain. In the Hearst Tower, the building "breathes." The "Icefall" water sculpture is not merely decorative; it is a psychrometric machine:

Evaporative Cooling: It utilizes harvested rainwater to naturally cool and humidify the atrium.

Radiant Flooring: This marked New York's first large-scale use of a capillary tube network beneath the floor, radiating cooling or heating while eliminating the noise and energy consumption of massive air handlers.

Battle of the Titans: Technical Comparison

Turning Torso (Malmö), 190 m: Achieves stability through a circular reinforced concrete core and an external steel "spine" that enables the 90-degree rotation of its floor plates.

CCTV Beijing (Beijing), 234 m: Defies gravity through a continuous loop design and an irregular structural skin that distributes stresses across an extreme cantilever.

Hearst Tower (New York), 182 m: Relies on the intelligent geometry of the Diagrid. By utilizing 85% recycled steel and eliminating corner columns, it proves that the avant-garde is not just about height, but structural efficiency.

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TURNING TORSO - SANTIAGO CALATRAVA

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FAMOUS CONSTRUCTIONS / CONSTRUCCIONES FAMOSAS

By José Miguel Hernández Hernández

The 20 milestones of the global skyline. A journey through architectural mastery.

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Frequently Asked Questions about the Hearst Tower, New York:

How does the 1928 base support the weight of the new tower?
In fact, it does not. Joseph Urban's original structure was hollowed out and acts only as an aesthetic shell. The weight of the glass tower is transferred directly to the ground through steel megacolumns that pierce the ancient base without resting upon it.

Why was 85% recycled steel chosen for the project?
It was a pioneering decision for New York skyscrapers to achieve LEED Gold certification. By combining the geometric efficiency of the Diagrid (which uses less material) with recycled steel, the building's carbon footprint was drastically reduced.

What technical function do the "diamond birds" (chamfers) serve?
The cut vertices at the tower's corners are not merely aesthetic; they serve to disrupt wind turbulence. By softening the corners, lateral pressure is reduced, preventing the oscillation effect caused by vortex shedding.

How does the "Icefall" climate control system work?
The lobby water feature utilizes rainwater harvested from the roof. This water helps to humidify and cool the air in summer through evaporation, working in conjunction with radiant flooring to optimize energy consumption.

Is the Diagrid system safer than a conventional one?
Yes. The redundancy of the triangular system offers superior torsional stability. If a node were compromised, loads are naturally redistributed through adjacent diagonals—a process that does not occur as easily in vertical pillar structures.

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José Miguel Hernández Hernández

International reference in the technical analysis of iconic and sculptural architecture. Specialist in the intersection between engineering, aesthetics, and vanguard design. Author of the bilingual technical books Turning Torso – Santiago Calatrava and Famous Constructions.

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