Nabih Youssef Associates

04/13/2026

Most hospitals are designed to survive earthquakes.
Few are designed to function through them.

When an earthquake hits a hospital, it sets off a chain reaction. The seismic waves enter the building through the foundation system and activate the building’s seismic frame. The frame deforms as the earthquake motion intensifies. Most buildings, even new ones, experience extensive damage.

Ceilings crack.
Piping strains.
Elevators stop.
Systems go offline.
Equipment loses calibration.
Critical care is disrupted, exactly when it’s needed most.

Nabih Youssef & Associates' solution: break the chain reaction altogether.

At Stanford, the strong earthquake motion is mitigated before it ever enters the building.

Friction pendulum isolators decouple the structure from the ground, lengthening its fundamentalperiod and significantly reducing the forces and accelerations transmitted upwards to the superstructure.

The reduced motion that remains is then managed by a steel moment frame, designed to stay essentially elastic at the Maximum Considered Earthquake, limiting drift and preventing permanent damage to structural elements. By controlling both forces and deformation, the effects that typically cascade through a hospital are suppressed at their source.

Systems remain intact.
Equipment stays operational.
Care continues.

The hospital doesn’t just stand.

It works.

03/05/2026

A one-million-square-foot hospital.
A steep hillside.
A few miles from the San Andreas Fault.

The perfect conditions for an extraordinary design challenge.

The UCSF Health Helen Diller Hospital at Parnassus is a 15-story, nearly one-million-square-foot acute care facility rising on UCSF’s medical campus in San Francisco. The building takes the form of a compact hospital tower whose floorplates shift and taper as it rises, creating a distinctive stepped profile. Large cantilevers extend the lower levels outward, while the tower above reads as stacked horizontal volumes designed to support the complex spatial needs of modern healthcare.

So, what makes this building so challenging?

The site is a steep hillside surrounded by existing hospital buildings, busy roads, and dense underground utilities, leaving a tight triangular footprint that forces the tower’s geometry to shift as it rises. At the same time, hospitals demand large, open, flexible floorplates. Reconciling those spatial needs with the irregular form of the tower, while designing a 280-foot-tall hospital in one of the most seismically active regions in the world, is what made this project such a remarkable design challenge.

The goal was to remain true to the architectural vision while still meeting the highest standards of seismic safety.

This is where the breakthrough came. Rather than relying on stiff shear walls that would lock the building into a rigid structural diagram, our engineers used steel moment frames supplemented by nearly 200 fluid viscous dampers distributed throughout the building. These devices act like shock absorbers, dissipating seismic energy, and controlling drift during earthquakes. Because the damping system does not need to be vertically continuous like traditional bracing, that allowed the architect’s vision free rein, rather than forcing the building into a regular grid.

The result is a beautiful building and a structural solution that quietly makes the architecture possible.

03/04/2026

If you recently received a letter from the City of San Francisco regarding its non-ductile Concrete Building Screening Program, we can help you deal with it efficiently.

The City is now evaluating the safety of certain concrete buildings that may be vulnerable to earthquakes. The new ordinance requires owners to complete a preliminary screening form to determine whether their buildings meet modern seismic safety standards.

We have seen this before.

When Los Angeles implemented its Non-Ductile Concrete Ordinance in 2015, owners received similar notifications. Since then, NYA has worked alongside hundreds, if not thousands, of property owners, guiding them, strategically, through evaluations, city submissions, and every step required for compliance.

We:

• help you understand the process;
• identify the minimum requirements; and
• complete those requirements cost effectively.

If you received such a notice, we are here as a resource for you, with extensive experience having previously handled the process for many of the most sophisticated building owners in the United States. Send us a direct message on Facebook, to learn more.

02/18/2026

Every year at NYA, we pause for something special: the Technical Excellence Forum, our annual engineering retreat.

It is a chance to build upon the skills we use to perform projects, get together and reconnect with things we value.

Alongside skill acquisition on soil structure interaction, and advanced FEA techniques, we reflected on three values lived by our founder, Nabih Youssef, and which shape our firm.

We reflected on empathy, the interest in trying to understand others.

We spoke about humility, the assumption that we need to keep learning.

And we thought about love, of what we do, and of who we do it with.

The experience of TEF is a reminder of who we are.

05/09/2025

We've reached a great milestone with the installation of the first of two tower cranes that will be used to construct the world-class UCSF Health Helen Diller Hospital. Visible from all over San Francisco, the bright red tower cranes will hoist approximately 20,000 tons of structural steel over the next several years to build this state-of-the-art hospital.

Nabih Youssef Associates is proud to be part of such an incredible project and a talented team. Onwards and upwards!

04/04/2025

Los Angeles Memorial Coliseum: The historic Coliseum is one of the most storied and premier sports venues in the world.

The Coliseum suffered extensive structural damage because of the 1994 Northridge earthquake.

NYA led a comprehensive retrofit effort to ensure public safety, while keeping the Coliseum's character intact.

The project also had an immovable delivery date, before opening day for the season.

To meet the challenge, a variety of unique strengthening techniques were utilized. New drilled caissons were added inside the building and pre-loaded with Osterberg cells. In the famous main entry peristyle, twelve-inch diameter cores were drilled down the entire forty-foot height of each historic existing column. Atop the stadium, a new steel-framed press box was designed and built during the summer of 1995 with detailing and welding techniques that incorporate lessons learned from research following the Northridge earthquake. The restoration was successfully finished in time for its reopening with the 1994 season.

Since that time, NYA's relationship with the structure has remained constant, and has involved adding luxury boxes, event spaces, and a press box, and reshaping the stadium bowl in a massive modernization.

The character of this historic landmark shines on into the future.

04/02/2025

Security, resilience, and innovation - the Los Angeles Police Headquarters shows the potential of elevated civic architecture.

This steel-framed facility integrates Buckling Restrained Brace Frames for lateral resistance, providing superior seismic performance for a mission-critical public building.

The Buckling Restrained Brace Frame system provides enhanced building performance in resisting large-magnitude seismic events with minimal damage. The LAPD Headquarters is one of the tallest applications of this advanced lateral system in a high seismic region within the United States, as well as being one of the first to be approved for real-world construction by the Los Angeles Department of Building and Safety.

04/01/2025

CATHEDRAL OF OUR LADY OF THE ANGELS: Designed by Pritzker Prize-winning architect Rafael Moneo, Our Lady of the Angels Cathedral is a landmark in downtown Los Angeles, built to stand the test of time. NYA engineered the exposed concrete walls to last over five hundred years, utilizing state-of-the-art material sciences. Advanced non-linear analyses and custom concrete mixes ensured structural integrity while maintaining the Cathedral’s spiritual grandeur.

09/23/2024

Nabih Youssef & Associates is performing the structural plan check review for the City of Inglewood for the new $600 million, 915,000 SF, 20,000 seat basketball arena. The arena is being constructed with a steel frame, precast seat risers, and a BRBF lateral system. The plan check includes 3 separate parking garages, 2 retail buildings, a pedestrian bridge, and all non-structural components including deferred approval packages.

Nabih Youssef & Associates is performing the structural plan check review for the City of Inglewood for the new $600 million, 915,000 SF, 20,000 seat…

09/13/2024

Congratulations to our incredible team! Your work on advancing seismic design is both impressive and deeply meaningful. What a beautiful way to honor Nabih Youssef's legacy!

Congratulations to our incredible team! Your work on advancing seismic design is both impressive and deeply meaningful. What a beautiful way to honor Nabih…

09/13/2024

2024 Best Project Awards California Region - Best Restoration/Renovation.
University of Southern CA United University Church, Los Angeles.

We are delighted to share that USC United University Church has been honored as one of the ENR California Best Projects winners in the Renovation/Restoration category!

University of Southern California United University Church (UUC) is a historically significant building transformation for the School of Dramatic Arts (SDA). The scope includes extensive architectural, structural, and building system upgrades, delivering a highly sustainable building with a goal of LEED Platinum with a new use that embraces the historic features of the building while creating a dynamic new home for SDA. The structural scope includes a demo and replacement of the existing stair from 34th Street to the Courtyard, removal and replacement of the existing elevator with a larger elevator, a new freight elevator in 3-story addition, theatrical platforms, structural support, and seismic bracing for theater pipe grid, rigging and lighting systems, and acoustic panels, new ceilings, seismic bracing for Audio Lab walls, and structural support for operable walls.

https://www.enr.com/blogs/12-california-views/post/59022-enr-california-announces-2024-best-projects-winners

Of 90 submissions to ENR California's annual Best Projects competition from across California and Hawaii, an independent panel of judges selected 30 Best Projects and 27 Awards of Merit.