1021 O Street State Office Building
West Sacramento, California
Excellence in sustainability
Presented by: Hensel Phelps
Region: ENR California
Owner: California Department of General Services
Main design company: HOK
General contractor: Hensel Phelps
Civil engineer: Morton and Pitalo
Structural engineer: Crosby Group
MEP Engineer: Mechanical FM cabin
Electrical subcontractor: Electric Rosendin
Associate Architect: Dreyfuss + Blackford
Energy conservation is a hallmark of this California state office building in Sacramento, one of the world’s first net-zero energy, net-zero carbon, and all-electric government office facilities. state The project team says the offices are a “benchmark” for state Department of General Services buildings, “setting a new standard of sustainability and flexibility for the state.” The 10-story, 472,000-square-foot building runs on 100 percent renewable energy through community solar agreements that result in 103 percent energy savings over baseline. This approach provides utility cost savings to the state and gave the local Sacramento company the customer commitment it needed to justify further solar farm development and investment. A centralized building management system enables real-time analysis of building performance and adjustment of mechanical systems, including a low-friction air supply system and a water-to-water heat pump. The building has 100% LED lighting and individual work lights and charging points for electric vehicles. It received LEED Platinum and CalGreen Tier 2 certifications. The exterior facade is overlaid with a precast/preglazed fiberglass reinforced concrete enclosure that improves the building’s insulation and improves thermal performance, according to the project team . The facade also responds to the different environmental conditions on each side.

Photo by Alan Karchmer
The project is noteworthy for other reasons. According to the competition entry, it was California’s first use of progressive design-build and saved the state 18 months, compared to traditional design-build. The fast track project was to temporarily house the State Legislature, and the team had a firm completion date to meet the Legislature’s schedule. The project was completed in June 2022, on schedule and under budget. Missing the target date would have cost the state up to $130 million in delays. In 2022, the team also had to deal with wildfires and an outbreak of civil unrest in the city center that included the deaths of six people, according to published reports.

The facade improves insulation, improves thermal performance and responds to the different environmental conditions on each side.
Photo by Alan Karchmer
