Mass Timber Innovation at East County Library
In designing the East County Library, we faced an inspiring challenge: how do you create a forest out of a building?
The answer led us to push the boundaries of mass timber design, resulting in a civic space that honors the Pacific Northwest’s natural heritage and the evolving future of sustainable architecture.
Forest as Inspiration
Standing amid towering trees, experiencing the interplay of light and shadow through the canopy, feeling the rhythm of intimate spaces opening into grand clearings—these natural patterns inspired us to reimagine how a 93,000-square-foot civic building could capture the spatial experience of our region’s beloved forests.
The forest is a gift to us. We have a public right to experience it, which correlates with the library as a public space—a place of reflection.— Brittany Shreiner, Design Principal
Nature Shaped Design
The forest-inspired design language permeates throughout the entire building. Double-height spaces at entrances and the central “living room” give the impression of standing in an old-growth forest surrounded by tall trees.
Emphasized by Timber
Columns extend through an acoustic ceiling tile (ACT) system, with the ceiling appearing to float free from the columns, emphasizing the full height of the space.
Mass Timber Innovation
Early in the project—and with the help of community voices—we chose mass timber as our primary building material for both its aesthetic power—natural, beautiful, and inspiring—and its significant environmental benefits. Mass timber construction dramatically reduces a building’s carbon footprint compared to traditional steel and concrete, a crucial consideration for civic architecture in an era of climate change.
Working with Timberlab, we orchestrated an ambitious system of 1,200 glulam beams and nearly 300 cross-laminated timber (CLT) panels, pioneering new approaches that pushed the boundaries of what’s possible with the material.
The scale of the project—with a target floor area of 51,000 square feet for level one—led us to select Type IV-HT (Heavy Timber) construction, which offered several key advantages.
Most importantly, it let us expose the heavy timber columns and beams without additional fire protections, as the material itself meets fire-resistant requirements through its dimensional specifications rather than added treatments.
This approach simplified wood-to-wood connections and allowed us to showcase exposed CLT throughout the building. It also made the double-height “living room” easier to accomplish with less stringent fire ratings, creating a more efficient, cost-effective construction process without compromising on aesthetics.
Type IV-HT Construction
Using Type IV-HT construction allowed us to expose the glulam beams and CLT panels while still meeting fire codes.
Crafting a Timber Canopy
Another key innovation was using “splitlams” (split laminated timber) to create large dimensional timber for columns and beams.
These splitlams were thoughtfully routed to create architectural reveals that tie in with the roof structure and reinforce the design concept of a forest canopy above. For dramatic effect at exterior corners, we combined separate splitlam profiles to create “mega columns” that visually anchor the building.
Altogether, this innovative timber structure became the foundation for our design, which thoughtfully alternates between intimate spaces and soaring clearings filled with natural light.
Constructing a Natural Flow
Compression and release principles inspired by forest landscapes guide visitors through the building. Glulam columns rise like tree trunks toward CLT ceilings, while wood-paneled walls and balustrades add warmth and texture throughout, creating a natural grid that perfectly suits the library’s programmatic needs.
Mass timber works really well for the structural grid of a library, where having a network of columns helps organize spaces, rather than being a limitation.— Dave Otte, Principal / Owner
Hybrid Structural System
Additionally, while mass timber forms the primary structural system, we also strategically placed concrete shear walls around the auditorium—benefiting acoustics while providing structural support—and at the east side of the building. This hybrid approach combines the warmth and sustainability of mass timber with targeted use of concrete and steel where most appropriate.
No Detail Too Big or Too Small
The attention to natural mimicry extends from the building’s grandest gestures to its finest details.
Looking up within the library, visitors experience the double-beam roof structure that embodies the forest canopy aesthetic. We created this distinctive ceiling plane using paired glulams and large splitlams with consistent dimensional reveals, establishing a visual rhythm overhead that suggests the variation in tree heights found in natural forests. This design language unifies all structural systems throughout the building while creating moments of wonder and discovery.
Historic libraries have this sense of grandeur, almost like a cathedral. Here, we wanted to create a natural cathedral—one where you look up and feel the vastness of the wood canopy above.— Brittany Shreiner, Design Principal
Taking Extra Steps to Preserve the Timber Aesthetic
For visual harmony, we specified the visible faces of CLT panels in fir to match the splitlam columns and beams, creating a cohesive material palette. We also paid special attention to the orientation of CLT panels at both interior and exterior applications, strategically positioning them to provide structural support at double-height spaces and roof overhangs.
Even the integration of building systems received meticulous attention. Working closely with contractors—including taking the unusual step of interviewing the sprinkler contractor directly—we developed innovative solutions to technical challenges.
Discreet Detailing for Fire Safety
Fire sprinklers were carefully coordinated within beam pockets and routed through the sides of double beams, preserving the clean aesthetic of the exposed timber.
Influenced by the Landscape
From the interior experience, our attention to detail extends outward. The building’s exterior features scalloped cladding inspired by tree bark and a roof deck offering panoramic views of Mount Hood and St. Helens. The result is a building in conversation with its broader community and context, inspired by Native architecture and our region’s natural heritage, that emulates the quiet comfort and simplicity of the forest.
Innovation in Sustainability
Built on a previously underutilized parking lot at NW Division Street and NW Eastman Parkway, the East County Library represents the largest project within a $387M county-wide initiative to modernize the local library system.
Given the scale and significance of this civic project, we thoughtfully approached sustainability as a fundamental responsibility and not just as a feature. This reinforced our commitment to mass timber as our essential building material.
Beyond its reduced carbon footprint, mass timber delivers a powerful innovation through its natural properties. It can enhance thermal performance, improve indoor air quality, and provide biophilic benefits that foster well-being. In fact, the structure provides natural fire protection through its physical char layer properties, reducing the need for additional fireproofing treatments.
This approach—using the timber itself as fire protection—represents a forward-thinking step toward new building typologies that leverage natural material characteristics rather than relying on chemical additives.
To ensure the material’s long-term sustainability, we developed a comprehensive approach to exterior wood treatment to protect the timber from weather and UV exposure. We applied a specialized three-coat system to exterior wood elements, preventing the natural greying that occurs when timber is exposed to the elements. For visual consistency, where beams extend from interior to exterior spaces, we used a minimal treatment that ensures a uniform appearance while maintaining the wood’s natural beauty.
By sourcing timber locally and engaging regional fabricators, we further reduced the project’s carbon footprint, minimizing transportation emissions while supporting the Pacific Northwest’s economy and forestry industries.
This sustainable approach demonstrates how sustainable materials can not only create cleaner, safer buildings but also strengthen and support local economies.
A Model for Civic Architecture
As Oregon leads the nation in mass timber innovation, East County Library demonstrates how this material can transform civic architecture.
East County Library embodies what we believe public architecture can achieve: a space that serves its community while pushing the boundaries of sustainable design. As mass timber construction continues to evolve, this project is a testament to what’s possible when innovation meets intentional design.
