Proj Overview

Project Overview

The Serif and the LINE hotel are both located in a 12-story, mixed-use residential building—with 200,000 ft² of residential space for the Serif and 140,000 ft² of space for the LINE hotel—on a triangular block in downtown San Francisco. The scale of this project was influenced by adjacent buildings and the challenging proportions of the triangular site.

The Serif has 242 residences (studios and one- and two-bedroom homes). Amenities include a landscaped rooftop solarium equipped with a library and bar, a chef-grade kitchen for private events, a fitness center and yoga room, a pet spa, a dog run, and 24-hour building security. The LINE Hotel has 236 guest rooms, as well as retail and dining, and is home to the Magic Theatre. The structure wraps around the irregular site, culminating in a flatiron corner at Market and Turk Street. It has a distinctive, bright-white facade and floor-to-ceiling windows.

“Early in the design process, we considered a metal panel rainscreen, precast concrete and GFRC [glass-fiber-reinforced concrete] as potential materials to achieve the three-dimensional, faceted facade. Ultimately, GFRC proved the most advantageous due to its light weight as compared with monolithic precast concrete, and its simplicity of detailing and installation when compared with a metal rainscreen panel system,” says George Tolosa, AIA, associate principal, Handel Architects.

The weight of a traditional precast concrete facade would have raised the cost of meeting seismic requirements. “Heavy cladding can substantially impact the cost of the building structure that has to resist the resulting forces when that weight is accelerated by an earthquake,” notes Tolosa.

The unusual floor plan configuration features various angles and curving conditions. By creating a series of repeating panels at different lengths and applying them in a staggered formation, the modular system was able to incorporate the various conditions seamlessly. To limit the number of individual forms needed to create unique panels, the precast concrete producer designed an “adjustable form” where the complex geometry could still be achieved, but the different lengths required only a simple adjustment.

Preinstalled Windows

The 28-ft-long windows were shipped to the GFRC production facility and installed directly into the panels to allow for more efficient enclosure of the structure. Traditionally, preinstallation of windows would require a horizontal joint between floors where two panels are stacked. When viewed in the building information modeling (BIM) model, this joint detracted from the desired smooth and chiseled appearance. Therefore, the design team chose to install a steel tube framing component across the top of the panel. The skin of the upper panel hides the header tube of the panel below. “This larger span needed additional support during storage, trucking, and installation,” notes Sean Fitinghoff, senior project manager, Willis Construction Co. “Once on the building and attached to the structure, the additional bracing could be removed. GFRC proved to be the best solution for the design shapes and providing the preglazing option.”

The GFRC facade complements the architectural character of neighboring historical structures along Market Street. The combination of the light color of the GFRC and the solidity of the panels creates a contemporary rhythm within the urban context.


2023 PCI Design AwardsBest Mixed-Use Building
Project Team


Group I, San Francisco, Calif.


Handel Architects, San Francisco, Calif.

PCI-Certified Precast Concrete Producer:

Willis Construction Co. Inc., San Juan Bautista, Calif.

Structural Engineer of Record:

Magnusson Klemencic Associates, Seattle, Wash.

MEP Engineer:

Interface Engineering, San Francisco, Calif.

General Contractor:

Lendlease, San Francisco, Calif.

Project Cost:

$350 million

Project Size:

400,000 ft²

Key Project Attributes

  • Construct a 12-story, mixed-use building in downtown San Francisco on an irregularly shaped site.
  • The use of GFRC reduced the weight of the facade, allowing construction of the structure to be more efficient and economical, while also achieving the desired depth and texture.

Project/Precast Scope

  • The project used 671 precast concrete panels (79,000 ft² of GFRC).
  • Panels range in size from 18 to 27 ft and feature a white matrix with white sand and aggregates, and a light-sandblasted finish.
  • The residential project was completed in September 2021; the LINE hotel opened the following year.