First US Net-Zero Timber Civil Building Underway

MONDAY, JULY 24, 2023

Work has reportedly begun for what is anticipated to be the nation’s first net-zero energy government office building made from cross-laminated timber in San Mateo County, California.

The County Office Building 3, or COB3, is expected to be the “new cutting-edge home” for over 600 county employees and will produce 100% of the energy to keep the facility functioning and operational.

The American Society of Civil Engineers reports that the five-story structure with a gross area of 207,000 square feet was designed as a testament to San Mateo County’s environmental stewardship,” as it plans to target Platinum certification under the U.S. Green Building Council’s Leadership in Energy and Environmental Design rating system.

The facility will combine various county functions that previously had been dispersed among several sites throughout the region in one facility, said Eric Long, a partner at San Francisco-based SOM, which was responsible for the architectural, structural engineering, and interior design of the new facility.

The building was reportedly founded on a concrete slab and deep concrete piles, with four steel cores and steel braced frames as its lateral support system. However, COB3 uses mass timber for its columns, beams and flooring.

As a result, the building features an estimated 70% reduction in embodied carbon compared with a similar structure made entirely of steel or concrete, Long said. Additionally, the building is I-shaped in plan, with narrow wings that measure 65 feet wide to facilitate natural ventilation and natural lighting throughout, reducing the facility’s energy footprint.

Long also explained that solar panel arrays on the COB3 roof and atop a nearby county parking garage structure are expected to generate all the electricity required for the building’s operations. Glazing on the north and south facades will additionally be recessed to help reduce heat gain.

According to ASCE, onsite bioretention planters are expected to absorb and treat 100% of the site’s stormwater runoff, rather than diverting that water to municipal treatment facilities.

“Timber wraps the lobby interior, and wood slatting continues as a motif throughout the building, echoing the exposed wood structural frame. The abundance of natural wood creates a soothing, visibly low-carbon environment,” writes SOM of the design.

“All occupants will benefit from biophilic design strategies—the use of natural materials, natural ventilation, and views of the surrounding landscape. While the floorplate maximizes daylight throughout the interiors, the bridging floors, between the two wings of the building, create social collaboration hubs.”

In addition to SOM, the design and construction team reportedly included Truebeck Construction, of San Mateo County, as the general contractor; ENGEO Inc., of San Ramon, California, as the geotechnical engineer; and Meyers+ Engineers, of San Francisco, as the mechanical systems consultant.

COB3 is expected to be opened by the end of year.

Other Recent Timber Projects

In March, construction was underway for an office building made from 100% mass timber in Wilmington, North Carolina. The 67,000-square-foot, four-story building will be part of the Live Oak Bank campus.

Work is being completed by joint building venture Swinerton and Monteith Construction, designed by architecture firm LS3P. According to reports, Swinerton’s sister company Timberlab will provide both the glue-laminated timber and the cross-laminate timber fabrications for the project. The building is expected to be completed in early 2024.

Then, earlier this month, it was reported that the our-story mass timber loft office building at Ponce City Market in Atlanta has topped out. Handel Architects is the Design Architect and Architect of Record for the project, which has been designed to target net neutral operational carbon, LEED Core & Shell certification and Fitwel certification.

The building will include 87,000 square feet of office space and 27,000 square feet of retail space, located at Ponce City Market. Amenities will also reportedly feature onsite daycare and medical facilities, direct access to the Atlanta BeltLine, bike storage and complimentary access to The Roof at Ponce City Market.

Full completion of 619 Ponce is expected in 2024.

Outside of the U.S., residential property management company Atrium Ljungberg announced in June what it is calling the world’s largest urban construction project in wood in Stockholm, Sweden.

According to the press release, the project will extend over 250,000 square meters (2,690,977 square feet) and will feature 7,000 office spaces and 2,000 homes in Sickla. Additionally, plans include a “vibrant, urban environment” with a mix of workplaces, housing, restaurants and shops.

Reports indicate that the area is currently an old industrial zone filled with former factory buildings and parking lots. The mass-timber development will span 25 blocks with 30 wood buildings. Work is expected to begin in 2025, with the first buildings reaching completion in 2027.


Tagged categories: Building design; Color + Design; cross-laminated timber; Design; Design - Commercial; Energy efficiency; Environmental Controls; Government; Green building; NA; Net Zero Energy ; North America; Office Buildings; Ongoing projects; Program/Project Management; Projects - Commercial; Sustainability; timber; Wood

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