Proj Overview

Project Overview

Designers of the new four-story government building in Martinez, California, wanted to provide a visual connection between the building skin and the surrounding landscape. They determined that precast glass-fiber-reinforced concrete (GFRC) panels would be the best way to achieve that vision.

While several materials were initially investigated, collaboration between the contractor, designers, and owner’s representatives led to the selection of GFRC panels, which were chosen for their low cost, durability, ease of maintenance, and aesthetic benefits. The choice allowed the team to integrate custom integral colors, a stone facade look for the clock tower, and custom designed “wave art” panels that visually recall the water in the nearby bay and rolling hills surrounding the city.

Panelizing the exterior skin with GFRC panels also resulted in faster envelope-closure during construction, facilitating one of the owner’s primary goals of maintaining an accelerated schedule.

Net Zero

To create the three-dimensional (3-D) wave panel design, the designers began with computer and 3-D-printed models. Then, they worked closely with the precast concrete producer subcontractor to develop fiberglass molds and mock-ups to determine the final finish and color. By arranging the panels in different combinations, including flipping some upside down, the team was able to create an entirely custom look using only three unique molds.

The clock tower, featuring textured GFRC, was designed to mimic the look of the natural stone featured in many of the nearby historic buildings, blending civic character with a warm and welcoming entry.

At the pedestrian level, retaining walls, planters, and bollards made from architectural precast concrete seamlessly match the GFRC. By using precast concrete panels that were almost indistinguishable from the original cultured stone, the team was able to cut roughly six weeks from the project timeline. While the use of GFRC slightly increased the upfront construction budget, the added benefits far outweigh the initial costs. The use of GFRC reduces the building’s energy use from the baseline standard, which helped the building achieve LEED Gold status. To enhance the energy efficiency of the design, spray-foam insulation was applied to the back of the panels in the shop to create a continuous and consistent thermal barrier.

Based on operational data since the building opened, the structure is now operating at Net Zero Energy rating.

 

Awards_
2022 PCI Design AwardsGovernment and Public Structure Honorable Mention
Project Team

Owner:

Contra Costa County Administrators Office, Martinez, Calif.

PCI-Certified Precast Concrete Producer:

Willis Construction, San Juan Bautista, Calif.

Architect:

Fentress Architects, Denver, Colo.

Engineer of Record:

Thornton Tomasetti, San Francisco, Calif.

General Contractor:

Hensel Phelps Construction, Pleasanton, Calif.

Project Cost:

$110.2 million

Project Size:

73,568 ft²

Key Project Attributes

  • GFRC panels deliver cost, durability, and aesthetic benefits.
  • Unique panel design was produced using just three molds.
  • The building achieved LEED Gold status and operates at Net Zero Energy.

Project/Precast Scope

  • Build a new, energy-efficient county office building.
  • The project included 215 precast concrete pieces.
  • Precast concrete erection was completed in one month.