Plumas County’s Health and Human Services Biomass Boiler Building becomes California’s first complete CLT structure

SAN FRANCISCO, CA, April 19, 2018 /24-7PressRelease/ — The ribbon cutting ceremony by the Plumas County Health and Humans Services Department for its new Biomass Boiler Building in Quincy, CA on April 6, marked the opening of the first building in California made entirely of Cross-Laminated Timber (CLT). CLT is establishing itself as a sustainable building material with a reduced carbon footprint and an inviting, natural aesthetic. Whereas limited uses of CLT were previously implemented across the state of California in buildings as a roof or floor system, the Biomass Boiler Building was constructed using CLT panels for the complete structural system to resist gravity and lateral forces, such as wind or a seismic event.

Owned by Plumas County, the industrial Biomass Boiler Building located adjacent to the Health and Human Services Department in Quincy, CA, includes approximately 2,000 SF of space. It houses an innovative biomass system using organic and sustainable waste material to generate heat for the Health and Human Services Building as an alternative to fossil fuels. The boiler is only the second of its kind in the U.S.; it is a community-scale, biomass boiler unit that runs on hog fuel, a coarse woody material generated as a byproduct directly from forest restoration and management activities.

Camille Swezy, Wood Utilization Program Lead of Sierra Institute, remarked, “The community of Quincy and Plumas County officials are very pleased with the new Biomass Boiler Building constructed entirely of CLT, now housing an innovative biomass heating system. Timber and wood products development is deeply engrained in Quincy’s roots, and the community is now thrilled to have a demonstration of wood utilization in a practical small-scale application.”

Originally, the Biomass Boiler Building structure was planned to be constructed with a prefabricated metal building system. Plumas County officials and the Sierra Institute decided to take the project in another direction to demonstrate the strengths and benefits of building with timber while also incorporating Plumas County’s most abundant natural timber resources. Plumas County officials worked with the design team to integrate mass timber into the building’s design.

“There was no precedent in California for a project that used CLT as the seismic-force resisting lateral system,” Associate Principal, Erik Kneer of Holmes Structures explained. “We developed a strategy in close coordination with the Plumas County building official that combined precedent in other states with a conservative yet responsible interpretation of the code. We provided a pathway to approval of the project without burdening it with an overly expensive or time-consuming solution.”

The architectural design of the building showcases the use of mass timber with completely exposed surfaces on the interior, and exposed wood underneath the roof eaves. The vertical surfaces of the exterior of the building were clad to protect the wood from the elements, UV, moisture and to provide additional fire protection.

CLT panels are constructed by layering kiln-dried lumber boards crosswise at right angles to the adjacent layers, and bonding them together with structural adhesives. Architect Matt Bowles of AMLGM explains, “From a design and coordination perspective, working with CLT is relatively simple. The panels are cut on a CNC mill based directly on the pattern drawings produced by the architect. Since the CNC mill can handle cutting complex geometry with ease and little cost increase, it opens up new design possibilities; including creating custom patterns, contoured window openings, and changing thickness along a given wall section. The best part is that it’s made from wood all the way through, so leaving it exposed is both cost effective and aesthetically pleasing.”

One of the many benefits of CLT construction is the reduced installation time and crew size required to lift, set and screw the engineered lumber panels into place. The time on the project from concept development to substantial completion of the Biomass Boiler Building was less than a year, with rapid delivery on design, approvals and construction being critical to have the building closed and protected before the 2017/2018 winter season. Erection of the primary superstructure occurred over just a one week period in December of 2017.

The design team was led by Wisewood Energy and included San Francisco-based structural engineers Holmes Structures and architects AMLGM. Project management and development was led by The Sierra Institute for Community and Environment on behalf of Plumas County.

Biomass Boiler Building – Quincy, CA
Size: 2,000 SF
Completion: April 2018
Owner: Plumas County
Developer: Sierra Institute for Community and Environment
Prime Consultant: Wisewood Energy
Structural Engineer: Holmes Structures
Architect: AMLGM
General Contractor: Houston Construction
Timber Fabricator: Sauter Timber
CLT Panel Manufacturer: Structurlam

Holmes Structures is a part of the international Holmes Group, with offices in California, Australia, Netherlands and New Zealand. Holmes Structures provides structural engineering throughout the western region of the United States. Holmes Structures has been honored with over 70 national and regional awards with notable projects such as the Adobe Campus in Utah, the seismic retrofit and renovation of 140 New Montgomery, and the Bay Area Metro Center. For more information, please visit

For the original version of this press release, please visit here