The Downey Laboratory Expansion blends DELTABEAM®, mass timber, and human collaboration to deliver resilience in one of North America’s most demanding seismic regions.
A future-ready lab for public health
The Downey Public Health Laboratory (LAPHL) will be central to Los Angeles County's ability to protect public health. When it opens, the lab will handle human, animal, and environmental testing, including epidemiological work on emerging infectious disease variants.
The building's mission demanded equally high performance from its structure. It needed to withstand major seismic events, meet vibration criteria strict enough for sensitive laboratory equipment, and provide long, open spans without consuming precious headroom.
DELTABEAM® in a high-seismic zone
Peikko has worked in seismic regions before, but LAPHL marks the first DELTABEAM® project in California—a state with some of the strictest seismic codes in North America. The design team developed a hybrid system that combines Peikko's DELTABEAM®, DuraFuse moment frames, and Mercer's 7-ply CLT panels. The system addressed the critical challenges:
- Seismic demands: In earthquake-prone California, the structure needed robust bracing and effective diaphragm force transfer. The DELTABEAM®-DuraFuse combination delivered both.
- Limited headroom: To maximize ceiling height, Peikko engineered continuous DELTABEAMs® with CLT and a thin concrete topping, achieving 20-foot spans within a 14-inch slab depth—a shallow structure that doesn't compromise strength.
"LAPHL is one of the most complex projects I've ever worked on," says Florence Soucy-Fortin, Project Engineer at Peikko. "Several experts had to collaborate to deliver a robust structural solution, and DELTABEAM® helped facilitate the coordination between all of the different connections involved."
The human side of engineering
Beyond the technical achievements, what set LAPHL apart was the collaboration behind it. "The engineers at Peikko went the extra mile," said Alejandro Esparza, Structural Engineer at HDR and Engineer of Record for the project. "Throughout the design process, they were responsive, supportive, and really helped move the project forward."
Esparza also sees potential in the combination of DELTABEAM® and mass timber for future projects: "The pairing of mass timber and DELTABEAM® is a compelling one because it merges concrete, steel, and timber into a system that not only performs well but also creates a nicer-looking soffit. Hopefully I'll get to see more of that system in future projects."
A benchmark for hybrid public buildings
LAPHL represents more than a successful project—it establishes a new standard for public health infrastructure in challenging environments. By combining Peikko's innovation, HDR's structural expertise, Mercer's mass timber panels, and seamless collaboration, the project demonstrates how hybrid structures can meet demanding requirements for resilience, efficiency, and design. For Los Angeles County, the result is a laboratory ready to strengthen the region's public health response for years to come.
Building confidence in collaboration
The Downey Laboratory Expansion shows what's possible when the right technology, teamwork, and trust come together. It demonstrates that hybrid systems, such as DELTABEAM®, can meet California's most stringent seismic requirements. It demonstrates that mass timber and steel can work seamlessly as partners. And it confirms that when engineers, architects, and builders share a common purpose, they can create infrastructure that genuinely serves their communities. As Alejandro Esparza put it best: "That collaboration made a big difference for us."
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Project facts
Location: Downey, Los Angeles County, California, USA
Project Size: 16,408 sq. ft. (1,523 m²)
Floors: 2 above grade
Completion Date: Spring 2026
Developer / Client: Los Angeles County Department of Public Health
Construction Company: New Creation Builders
Structural Designer: HDR Engineering, Los Angeles
Architect: HDR Architecture, Los Angeles
This article was originally published in Peikko’s customer magazine Connections 2026.