How buildings have changed since 9/11

From security check-ins to stronger structures, office buildings have transformed.

September 10, 2021

On the morning of September 11th, 2001, Peter Riguardi was in a conference room on 52nd Street and Park Avenue.

The President of JLL’s New York Region had entered the building that morning with minimal security protocols and set his belongings down in a private corner office before taking on the day’s meetings.


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“I can remember it like it was yesterday,” Riguardi says. “Someone walked into the conference room and said a plane had hit the World Trade Center tower. All of us thought it was a small plane and turned on the TV. At that point, we knew it was something completely different, something devastating.”

Two decades later, skyscrapers and office buildings around the globe have changed dramatically. Adjustments to building codes made by the International Code Council, as well as a general culture of increased security, has led to a wide range of changes to office life, from security checkpoints to design changes in the construction phase.

“September 11th dramatically changed the office environment, and you can see that in what has been built on the site of the former Twin Towers,” Riguardi says. “What was built since is, from every standpoint, so much better than before, from the quality of buildings to the light and air inside offices. It’s a testament to the intentions of the people who got behind rebuilding it: to honor the people who lost their lives and to show the people who created the horror that we bounced back better than ever.”

Security, transformed

Before the attacks, accessing office buildings was much easier. In some cases, visitors would sign in at a front desk. In others, that wasn’t even required.

Visitors now typically check in and register at a security desk that scans a photo ID, and employees need a special key code or badge to gain access to the building.

“Immediately after the attacks, the changes to security were more extensive and bags were being x-rayed as you entered buildings,” Riguardi says.  “Eventually it scaled down to mostly involve turnstiles. Younger people may not even see the connection to September 11th as they swipe their badges — you just don’t come and go from buildings anymore.”

Buildings also became more secure by way of cameras and alarms, and by use of security programs and emergency response planning, says Mark Anderson,  Director of Security / SVP, JLL – Aon Center.

“Even more so today, buildings are designed with security and life safety measures in place as tenants demand a safe work environment,” Anderson says.  “Today, the technology has been refined to provide greater safeguards and a greater experience for its users.

Design changes

Architects and developers design office buildings differently today, often with external barriers that prevent vehicles from getting too close.

“There has been a greater focus on blast resistance standards,” Riguardi says. “Buildings are built stronger at the base and the glass won’t shatter.”

Case in point: One World Trade Center. The high-rise building that rose on the site of the former World Trade Center buildings has a concrete core made of the strongest concrete ever used in a skyscraper. Its 185-foot base is designed to prevent truck and other street-level bombings, and there are extra wide stairwells in addition to separate stairs and elevators for first responders.

“What happened in the years following the attacks, thanks to commitments from people like Larry Silverstein to redevelop the site, is that we have seen a transformation in construction,” Riguardi says. “The quality of a building’s construction has been elevated — from the strength of the buildings to the light and air and ceiling heights in offices. Since then, we keep pushing the standards higher and higher — and COVID-19 is taking it to another level.”

Evacuation procedures

It’s not just the buildings that changed. The events in 2001 proved the necessity of a collaborative effort and approach for building owners, managers, tenants and employees to establish comprehensive emergency response plans, Anderson says.

Emergency training and drills used to be perceived as a formality. After the attacks, there was renewed interest and demand for these programs. 

“It goes without saying that preparation is key for emergencies and those who are prepared will fare better than those that do not have an emergency plan,” he says. “The events of September 11th have reinforced the importance of emergency response planning.”

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