Shining a Light on Mass Transit - San Francisco Style

By Randy Reid

While 875,000 people call San Francisco their home, approximately 25.8 million travel to the city annually. So, it was a major triumph for Auerbach Glasow to design the lighting for the Salesforce Transit Center. The multimodal, LEED Gold transit facility is owned and operated by the Transbay Joint Powers Authority, and located in the heart of the city. Yukiko Yoshida, Sabra Zacharias, and Patty Glasow sat with me to share about this eleven year, 1.5 million square foot, multimodal hub project.

The project design began in 2008, when Pelli Clarke & Partners, formerly Pelli Clarke Pelli Architects, hired Auerbach Glasow, formerly Auerbach Glasow French, to create the lighting design. César Pelli (1926-2019), and Fred Clarke, world-renowned architects and founders of Pelli Clarke Pelli, were both actively involved with the project.

With four floors of unique lighting throughout including overhead lighting, accent lighting and lights through the Light Column, the team had a large project of utilizing lights in different ways – and with a decade of changes to the lighting industry, they had to adjust to stay current and utilize what was best for their project.

The Salesforce Transit Center (STC), formerly Transit Center, the name changed due to a naming rights agreement, is four blocks in length, six-stories high (four-stories currently open to the public) and one block wide. The ground and second levels have restaurants and wellness services, and an outdoor rooftop park occupies the fourth level. City and inter-city busses arrive and depart on the first and third levels and a future train concourse and platform will occupy the bottom 2 levels (the train box already exists). It is an impressive modern style transit hub. From an overhead drone shot, STC’s lush green park takes center stage and is one of the Bay Area’s crown jewels.

The ten-year design had several delays which caused headaches for everybody involved. As Auerbach was conducting their original lighting design, the TJPA updated their risk and vulnerability assessment. Since San Francisco is such a large tourist-based city, and home to earthquakes, they had to worry about both terrorism and structural soundness in case of natural disasters. As the security plan evolved, the architects changed their design, and Auerbach had to do the same with the lighting. Although the update caused some delay, San Francisco has a more secure facility.

The initial design began with fluorescent sources in 2008, and there was much debate about the practicality of LED. At that time, the Auerbach team did not feel there was enough evidence that LED was the correct choice. As the design continued into future years, LED became the obvious solution for downlights. But because the light fixture spacing was already set with sprinklers, speakers and other mechanics, there was no flexibility in the repositioning of LED downlights. Therefore, each LED luminaire had to be a one-for one replacement of the original fluorescent downlight design.

Construction of the underground phases began in 2010 even before the above-ground design was complete. In 2014, with the design finished, the above-ground construction launched.

After many RFI’s and submittal reviews, with most of the fluorescent fixture types ultimately replaced with LED products, the STC opened in August of 2019.

At the heart of the building, the Light Column supports a central skylight, allowing natural daylight to reach the train platform 6 levels below the park. During multiple focusing sessions, Yukiko rose 75 feet in the air with a construction worker in a lift to ensure precise aiming of the projectors. As Yukiko aimed the fixtures from the lift, Sabra was on the top floor confirming the beam patterns lined up perfectly. Sabra said, “I would run up to the roof and call Yukiko and tell her to move it by 5 degrees, then I would run down to each level to ensure the shape of the beam was consistent on all levels at different colors.” Auerbach Glasow specified Lumenpulse color changing fixtures to illuminate the Light Column. The color for the Light Column changes every hour.

Additionally, the team made nearly all lights dimmable, allowing for full control and flow from day to nighttime using Lutron controls. Yukiko said that there are different scenes for daytime, sunset evening, and after-hours.

City buses enter and exit at grade level as weekday commuters walk through the STC directly in front of the busses. Patty emphasized the importance of safety yet elegance in this high pedestrian traffic area. The design architect wanted a practical fixture, but not a typical highbay. SPI answered the call, creating a custom pendant luminaire that added the practicality of a highbay, in more of a decorative design.

Huge round fixtures are located on the third level. They consist of simple strip fixtures above resin diffusers. The diffuser is segmented in pie-shaped wedges for accessibility. An architectural detail was added to give the luminaire a recessed effect. Sabra said, “The quality of light is rather unique in that it is very comfortable for a transportation hub. The diffused light is bright and pleasant at all hours. You feel very safe.” Patty added, “The light feels good during the day as it blends with the daylight.”

On the fourth floor, which is the park level, Auerbach Glasow designed the lighting at the canopies that exit at the park level. HLB Lighting Design conducted the design for the park level including the landscape lighting which is 3000K. In describing the exterior light, Yukiko said, “Since the exterior lighting is only on at night, we don’t have to worry about blending with daylight. So 3000K on the exterior was a great choice, and we selected 3000K for the fixtures we specified on the park level.”

— Patty Glasow

On the ground level, which needed to blend with daylight, there is no landscape lighting, so all building-mounted lighting on the ground level is 4000K, which is the same as interior lighting. Maintaining the same color temperature between the exterior and interior helps blend the line between where outside ends and the inside begins. The building’s exterior features an eye-catching curving mesh awning, where large columns scale the building. The column lighting was mocked up in house and later at the site. During the office mockup, Sabra explained, “We stacked empty water jugs together and wrapped them in white paper to simulate the columns.” BK Lighting fixtures are attached at the bottom of the curving mesh awning to provide general lighting for pedestrian circulation, and BEGA spotlights are located at the top of the angled columns to highlight the columns.

I asked about the financial aspects given the long design time. Patty said that the fees were based on a traditional architecture model in that they were to be paid in phases, saying, “It was challenging, and there were additional services and ongoing discussions on how to deal with delays from a fee standpoint.”

Larry French, who left the firm in 2016, was the principal in charge of the project, but, since the design lasted more than 10 years, Auerbach had 18 different people work on the project. Yukiko was the original project manager and lead designer. Sabra joined the team during design development as lead designer for multiple levels. Other contributing designers for the project were: E. Sara McBarnette, as well as former Auerbach Glasow designers Marlene Lieu and Neha Sivaprasad. Patty explained, “Yukiko and Sabra were truly the stability of the design, since they were involved from the beginning, ensuring that the design elements from the original design, the new design, and the execution of the project stayed similar.” The duo worked relentlessly to warrant that this long project is worth a visit for both tourists and locals alike. ■

KEY MANUFACTURERS:

Exterior column lighting: BEGA

Canopy mounted lighting: BK Lighting

Linear: Insight Lighting, Elliptipar

Controls: Lutron

Pendant & surface mounted downlights: SPI Lighting

Recessed Downlights: Gotham®

Light Column lighting: Lumenpulse

AWARDS: 2 IES Awards of Merit. One for the entire project and one for the color changing Light Column

DESIGN TEAM:

Lighting Design: Auerbach Glasow, HLB Lighting Design

Design Architect: Pelli Clarke & Partners

Architect of Record: Adamson Associates International, Inc.

Landscape Architect: PWP Landscape Architecture

Electrical Engineer: Buro Happold and WSP