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skyscraper demolition

What Happens When a Skyscraper Outlives Its Useful Life?

After more than a century of skyscraper construction, many aging office towers in Manhattan are in need of extensive renovation. Some are architectural gems loved by nostalgic New Yorkers like the Art Deco monuments of the 1920s and ’30s, while others are just generic, asbestos-filled symbols of corporate gluttony.

Built in an era of cheap energy, many post-war Manhattan towers have facades of single-glazed glass, and structures that can’t support the weight of additional insulating glass. Many have low ceilings, tight column spacing, and inefficient heating and cooling systems. Often these have become even more cramped by having to accommodate the infrastructure of modern information technology. Buildings like these — and others that might take decades for owners to see a return on their renovation investment — may be good candidates for demolition. Replacement towers could provide owners with more space at higher rents and consume less energy. But to tear down and rebuild a skyscraper in a dense city like New York requires navigating a patchwork of zoning laws, NIMBYs, and engineering challenges.

Financial giant JPMorgan Chase has said it plans to take on this challenge by demolishing its headquarters on 270 Park Avenue to construct a new office tower for 15,000 employees. The 70-story replacement building would be as much as 500 feet higher than the current structure and contain an additional one million square-feet of space. At 707 feet-tall, 270 Park Avenue would become the tallest building in the world ever to have been torn down, with the exception of the World Trade Center attacks on Sept. 11, 2001.

Despite spending millions on a 2012 renovation of 270 Park Avenue, which at the time was hailed as the largest ‘green’ renovation of a headquarters building ever, Chase says it has pushed the existing structure to its limits. It currently has about 6,000 employees crammed into the 52-story tower, which was built for 3,500 Union Carbide employees in 1961. So why not just add more floors to the current structure? That option would be preferred by some who believe the building deserves protection because it was designed by trailblazing woman architect Natalie de Blois and well-known architect Gordon Bunshaft, both of Skidmore, Owings & Merrill (SOM).

If Chase were to add-on to the old structure, it could conceivably double its existing square-footage to nearly 3 million square-feet — more than One World Trade Center — as long as it preserved some existing building elements like parts of foundations or facades. Alterations to old buildings are generally allowed to follow old building codes (with exceptions for safety), which is often advantageous to developers looking to maximize floor space. For example, Cove Property Group is in the process of adding 17 new office floors on top of its existing eight-story office building Hudson Commons. Much of the existing structure is being reused and they’ll shave a year off of construction time compared to building from scratch.

270 Park Avenue
JPMorgan Chase plans to demolish its head office at 270 Park Avenue in Midtown East to build a new office tower for 15,000 employees.(Credit: Google Satellite)

Perhaps the reason why Chase would prefer to replace its headquarters rather than build an addition is the generous zoning rules now governing the area around Grand Central Station. As other submarkets attracted new office developments and major corporate relocations, New York City Mayor Bill de Blasio — and Mayor Bloomberg before him — spearheaded Midtown East rezoning to spur reinvestment in the area. The rules are supposed to help keep the critical submarket around Grand Central competitive.

“Preservation is one tool to create a dynamic economy, but so is development,” said Carol Willis, an architectural historian and founder of The Skyscraper Museum in New York City. She explained that many of Midtown East’s buildings are competing for tenants with the new state-of-the-art subsidized towers at Hudson Yards and the World Trade Center. “Midtown needs to answer the demands of the 21st century and shouldn’t be disadvantaged.”

So how big can developers build under the new Midtown East zoning? In Manhattan, new construction must conform to predetermined floor area ratios (FAR), the ratio of total building floor area to the area of its zoning lot. Each zoning district has a FAR which, when multiplied by the lot area, produces the maximum amount of floor area allowable. The new Midtown East zoning allows increased FAR in exchange for developers funding public transit or street improvements. For example, SL Green Realty Corp. agreed to fund $200 million worth of transit improvements in and around Grand Central Terminal, in exchange for the right to build the 1,401-foot-tall skyscraper One Vanderbilt. JP Morgan Chase is purchasing development “air rights” from landmarks in the surrounding district in order to build its larger headquarters — which it hopes will be finished by 2024 — and it will pay the City a minimum contribution of $61.49 per square foot to fund public projects, which will likely include improvements to the many subway tracks running directly beneath 270 Park Avenue.

This won’t be the first time a pile of rubble existed at the 270 Park Avenue site. Chase’s current tower actually replaced a 12-story, stone-clad building that contained the Hotel Marguery and 108 luxury apartments. Built in 1917, the building — home to Nikola Tesla and other celebrities — was hailed as the largest apartment building in the world and its rents were among the most expensive before it was torn down in the 1950s. The tallest building ever conventionally demolished was the Singer Building in New York City, which was once the tallest building in the world — however briefly — at 613 feet. The 41-story tower was dismantled in 1968 piece-by-piece to make way for a 54-story, 743-foot-high structure known today as One Liberty Plaza. The 12-story base of the Singer Building filled an entire blockfront but the tower above was a relatively narrow 65 feet x 65 feet, making for easy dismantling.

We should perhaps thus be thinking of tall buildings as perpetual entities with lifecycles potentially exceeding 100 or 200 years, while designing them in such a way that they can be creatively adapted for potential future uses.

“In many cases, it does make sense to tear down and replace a high-rise, especially if it’s outlived its practical usage,” said Council on Tall Buildings and Urban Habitat (CTBUH) Executive Director Antony Wood. “There’s really no precedent for tearing down 200-meter-plus towers. We should perhaps thus be thinking of tall buildings as perpetual entities with lifecycles potentially exceeding 100 or 200 years, while designing them in such a way that they can be creatively adapted for potential future uses.”

U.S. cities account for half of the world’s 100 tallest demolished buildings according to CTBUH data. This should come as no surprise given that the modern skyscraper emerged in Chicago and New York City in the 1890s. About a quarter of the 100 tallest demolished buildings were built between 1890 and 1920, while high-rises built in the 1970s have accounted for another quarter. The average lifespan of the tallest demolished buildings is only 41 years, highlighting Wood’s point that engineers and owners need to consider how their structures will be used decades or even hundreds of years in the future.

In 2016, to make way for One Vanderbilt, SL Green demolished a block full of buildings including the 22-story Liggett Building and 18-story Vanderbilt Avenue Building, both very old but not considered historically significant. Over on Sixth Avenue in the Garment District, developers Isaac Chetrit and Ray Yadidi are planning to tear down a 20-story office tower to make way for an 80-story mixed-use skyscraper, but first they must wait for an existing tenant’s lease to expire in 2020.

skyscraper demolition
One way to demolish a skyscraper is top-down disassembly. A “hat” wraps the top three floors to withhold noise, dust and debris while the construction team tears down the walls and floors. The “hat” continues to move down the building as floors are removed. Credit: Despe

There are dozens of other examples of high-rise demolition in New York City and throughout the world, though many of them were not razed to make way for new construction. The 380-foot-tall Ocean Tower on South Padre Island, Texas was torn down one year into its construction after cracks were discovered in its concrete and the building began to sink. Other high-rises, such as the 341-foot-tall Edificio Windsor in Madrid, had to demolished after sustaining heavy fire damage.

Planned or not, razing a tall building is a major undertaking. The most common method, using explosives, often takes months of painstaking preparation to survey the structure and prepare it for the blast by removing non-load bearing walls, weakening support structures and placing the explosive charges. The largest building ever to be imploded in this way was the 29-floor JL Hudson department store in Detroit, Michigan. Clearing up debris afterward can also take a very long time.

When carried out correctly, implosions can be achieved with a high degree of accuracy. For example, the 1991 implosion of Orlando City Hall – which was featured in the film Lethal Weapon 3 – reportedly didn’t crack a single window on an adjacent building just several feet away. But, if something goes wrong, the results can be disastrous. In 1997 nine people were injured and a 12-year-old girl was killed by flying masonry during the demolition of the Royal Canberra Hospital in Australia.

Due to 270 Park Avenue’s crowded location and the building’s height, an implosion will not be safe or practical. Chase will need to consider some creative, slower alternatives. In 2008, Kajima Corporation demolished its own high-rise headquarters buildings in Tokyo using the “Cut and Take Down Method.” The process involved knocking out the bottom floor and lowering the structures above it on computer-controlled hydraulic jacks. Stop-motion footage of the system makes it look as though a 20-story building is sinking into the ground.

Another method was used in New Zealand after severe earthquakes in 2010 and 2011 irreparably damaged several high-rises in Christchurch. Demolition crews there used a 213 foot-tall high-reach mechanical excavator nicknamed “Twinkle Toes” to carefully pull down the buildings. The long arm of the excavator was equipped with video cameras on its claw allowing the operator to see what he was destroying. Something like that couldn’t possibly reach far enough to be useful in tearing down Chase’s skyscraper.

Perhaps the most likely method for demolishing 270 Park Avenue, which Chase has said will commence early next year, will be a top-down disassembly. Taisei Corporation has perfected this method using a “hat” to wrap the top three floors of the structure. The covering withholds noise and dust and debris. As soon as the construction team tears down the walls and the floors, it continues to the next floor below. The “hat” continues to move down the building as floors are removed. Another company from Italy, Despe, is applying a similar technique. As the work progresses, the platform descends in a controlled manner until it reaches ground level and the building has been completely demolished.

A full-block site like 270 Park is an extraordinary anomaly in Midtown. Plus buildings completed before 1961 were allowed much more floor area than would be allowed under current zoning in most parts of the City.

Will the reconstruction of 270 Park Avenue usher in a new wave of high-rise demolition throughout Manhattan, as developers look to modernize the City’s aging office buildings? Probably not, said Carol Willis. “A full-block site like 270 Park is an extraordinary anomaly in Midtown. Plus buildings completed before 1961 were allowed much more floor area than would be allowed under current zoning in most parts of the City,” she explained. Besides, many TAMI tenants (technology, advertising, media and information) prefer the character and industrial chic of older buildings. Take Google for example, which over the last decade has transformed massive old buildings in Chelsea and the Meatpacking District into a tech hub.

Perhaps JP Morgan Chase’s unprecedented teardown of its 58-year-old Park Avenue headquarters and the soaring tower that will replace it can help give Midtown East a similar shot in the arm. Rebuilding rather than relocating to Hudson Yards or Downtown means that 15,000 employees will remain in the area, and public transit and infrastructure will see major improvements. But will tearing down and replacing tall buildings with even taller buildings damage the character of urban neighborhoods? Is Midtown East finally becoming the Gotham that Hugh Ferriss’ Metropolis imagined, or is this simply the best solution to ensure this historic area remains one of the world’s premier business districts?

Politics and social commentary aside, skyscrapers are one of the most impressive engineering marvels of the past century. Even though they are built to withstand the relentless forces of gravity and wind, these city-defining towers are no match for the march of commerce and the vagaries of popular opinion.

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