First OSHPD-Approved Light-Gauge, Steel-Frame Structure Leverages Digital Fabrication for Rapid Growth
In an industry where it is status quo for skilled nursing to be part of continuing care retirement communities, a new kind of skilled nursing and rehabilitation facility is “growing” in Chino, California—Trellis. The first project of a collaborative statewide development program, the 59-bed, 40,000-sq.-ft. Trellis facility in Chino is also the first light-gauge, cold-form steel-frame structure to ever be approved by the California Office of Statewide Health Planning and Development (OSHPD), serving as a template to streamline lengthy aspects of the state agency’s approval process.
“Granite Development approached DPR to be a part of a collaborative team and provide strategic counsel through the entire life cycle of its vision for the Trellis skilled nursing facilities that are planned throughout the state,” said Brian Gracz, who leads DPR’s San Diego business unit. “We are helping them in the earliest stages of development with site assessment and rapid budget feedback for property comparisons, as they focus on creating a new kind of skilled nursing and rehabilitation experience in California.”
The team, which includes Granite, DPR, Darden Architects, Kitchell and others, wanted to avoid the inherent issues of wood structures (e.g., pest control, water intrusion, fire protection), and improve speed of construction, reliability, and scalability of the program. They incorporated a load-bearing digitally fabricated light-gauge steel framed structure through Digital Building Components, which uses digital fabrication to transform computer models directly into precise-to-spec building assemblies.
Benefits of Light-Gauge Steel Framing and Digital Fabrication
- Efficiency and Scalability: Off-site digital fabrication enables key components of the light-gauge framing to be produced together in a safe and controlled environment, reducing costs while enhancing safety and construction efficiency. Compared to a traditional wood-frame structure, the team shaved about four weeks off the schedule, and about $100,000 in general conditions cost on the first Trellis project. When multiplied by several facilities across the state, the savings grow exponentially, allowing Trellis to move into the nursing facilities sooner and begin positively impacting the lives of its patients.
- Seismic safety: Lighter than concrete, or hot-rolled structural steel buildings of the same height, cold-form, light-gauge panelized structures have proven to be strong and flexible enough to move with seismic activity instead of against it. Last summer, DPR helped assemble the tallest cold-formed, steel-frame structure ever to be tested on a shake table. The six-story building withstood a simulation of 150 percent of 1994’s 6.7-magnitude Northridge, California earthquake, shaking and rocking, but remaining structurally intact and safe. The structure performed so well, the team ended up dismantling it themselves, since it never failed through testing.
Challenges and Design Strategy
- OSHPD approvals: Due to the prevalence of wood-frame construction for these types of facilities, the Trellis facility was a first for OSHPD. The regulatory agency’s preference is that structures be built on-site for easy inspector access. To help with the process, the team worked closely with OSHPD to coordinate having an inspector on-site to check and sign off on the first 100 digitally fabricated panels. After that, only 30 percent of the panels needed to be inspected on-site and the first project is expected to be completed in early 2018.
- Strategic structural design: California has different seismic zones that affect structural design. To account for that, the team is constructing the Chino facility to meet the seismic requirements of one zone higher than necessary so the exact same structure can be replicated in different locations. Because the designs of the facilities are the same, OSHPD approval time is being drastically improved. In addition, different regions have varying pollution requirements. Designs of the facility were created with and without a diesel particulate filter, so both options could be approved by OSHPD simultaneously.
- Since starting the Chino project, the team has gotten two projects approved through OSHPD, and is now working on the third. By the end of 2017, the team looks forward to having three facilities across the state approved–with more to come.
Posted on October 12, 2017
Last Updated August 23, 2022