August 31, 2023

Mass timber building spotlights Washington’s roots

Clesi

Hellstern

Peterson

Over the past decade, responsibly-sourced mass timber has proven absolutely essential in the journey towards decarbonization — its lower embodied carbon, seismic resilience, and fast build times giving clients and designers alike a reason to endorse it.

Miller Hull started incorporating mass timber into its projects as early as the 1980s. The firm has worked with mass timber in a variety of hybrid iterations, from the structural system of the Bullitt Center to the FSC-certified wood of Bainbridge City Hall, and has used not only cost and program to dictate the wood’s treatment, but also the concept of Biophilia; how can this material help to create a memorable and inviting place?

Someone who enters into a space and is met by soaring beams or a reclaimed wood stairwell is much more likely to experience the benefits of Biophilia, or the sense of wellbeing that is created through exposure to natural elements like wood, stone and daylight.

Images courtesy of Miller Hull [enlarge]

Exterior rendering of Newhouse at night.

As designers who prioritize sustainability, we typically try to incorporate biophilic elements into our projects using low-carbon materials to reconnect users with the natural world, and lessen our impact on the earth. For the Newhouse Building replacement effort on the capitol campus, the use of timber was just as innate to the project as it is to our designers.

For one, the project is located in a region where timber is plentiful, giving us an opportunity to showcase Douglas Fir, one of the state’s most precious natural resources. Secondly, invigorating regional economies and incorporating this local wood throughout the design is a nod to the hundred-year-old beloved building Newhouse is to replace, a callout to the region, and a safeguard for its future.

The Newhouse Building Replacement takes the innovative use of mass timber a step further, exploring the ways a building might reflect the region through its material structure, and introducing the world to the first all non-toxic acoustic system.

Showcasing salvaged timber

Built in 1911, the state’s campus contains a variety of beloved historic buildings. The Ayer and Carlyon Press houses are among these hallowed places, and are architecturally significant in their own right; the Ayer House was designed by Elizabeth Ayer, the first female architect to graduate from the University of Washington; while the Carlyon embodied the quintessential Craftsman-style bungalow, and was the only remaining residential building to front 14th Avenue.

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Close up of the reimagined non-toxic, acoustic dowel laminated timber (ADLT) system.

Despite their rich histories, the structures were built to be homes, not offices, a mismatch that grew increasingly evident as the buildings aged. After the press was relocated to the first floor of the Legislative BuildingAyer and Carlyon served as extra space for the Senate. The land on which the houses sat, however, had already been slated for redevelopment, its 1982 master plan identifying the parcels as a possible location for new construction. Due to the historic nature of the homes,the state began searching for buyers who could relocate the buildings.

When this proved unsuccessful, Miller Hull and the community lobbied for deconstruction, allowing building parts to be disassembled and reused. Our team began incorporating salvaged elements into our design concepts for Newhouse, and when we developed a strategy that involved converting salvaged timber into a four-story art wall in Newhouse’s grand foyer, the state enthusiastically gave its support.

The four-story art wall sits at the head of what will be the mixing chamber, or the social heart of the building, and if walls could talk, this one would have plenty to share about newsroom narratives of the past, and spirited interactions of the future. Made with many different parts of reclaimed lumber, the wall is designed to represent the varied landscapes of the great Pacific Northwest.

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Rendering of the Newhouse mixing chamber featuring a four-story art wall constructed of salvaged timber.

A non-toxic, dowel laminated timber (DLT) system

Acoustic insulation is vital for large spaces, whether it be providing aural clarity, preventing reverberation, or absorbing errant and distracting noises. Uniquely vital to civic buildings, acoustic design helps deliver the amplification necessary to promote engagement between citizens and state.

But there’s one problem: acoustic insulation can be unsightly and unhealthy. Routinely tucked away, these systems are often made available through the reduction of room height and the dropping of ceilings. Their negative environmental and health implications are also significant, containing chemicals like formaldehyde, flame retardants, and antimicrobials, along with glues that all contribute to reduced indoor air quality, and whose production alone creates a significant number of emissions. These chemicals bring a harmful side to a building material that is intended to be environmentally friendly.

Our team sought out alternative acoustic products. Crafted by StructureCraft, the selected DLT panels for the floor decks are essentially composed of two parts: the wood members that are doweled together without the typical formaldehyde-laden glue, and the insulation product that is inserted into the grooves between the wood members. This configuration leaves only neatly woven wooden strips visible, while the insulation material is mostly concealed within the grooves. This product is called acoustic dowel laminated timber (ADLT). Typically, most dowel laminated timber from StructureCraft uses spruce-pine-fir sourced from British Columbia. However, because this is a civic building, the state requested that the lumber used be from Washington.

Throughout our team’s analysis of the dowel laminated timber, we discovered that 10-15 percent of the acoustic insert actually contained formaldehyde. Although no adhesive was needed to attach the strips together (as they slid into one another like puzzle pieces) the composition of the inserts themselves was not toxin-free. What followed was a process our team often engages in during our Living Building Challenge work; the collaboration with a manufacturer to develop a healthier solution.

After testing numerous options, balancing acoustics, constructability, and cost, our team determined that the best product for the acoustic insert was a material created by FSorb, a company based just north of the campus that develops chemical-free wall and ceiling panels. With a formaldehyde-free acoustic insert t combined with the dowel-laminated timber, an all-natural, economical, and beautiful acoustic system is now available, heightening the health and sustainability of the project, and giving other buildings the opportunity to do the same.

The Newhouse replacement will become an expression of the legislature’s most current and pressing priorities, addressing climate, human health and local economies through the careful selection of materials.

Nick Clesi is an architectural designer at Miller Hull, a member of the firm’s mass timber lab, and the project manager on the Newhouse project.

Chris Hellstern is Miller Hull’s Living Building Challenge services director, the sustainability lead on the Newhouse project, and authored a book titled "Living Building Education."

Gabrielle Peterson is Miller Hull's strategic writer.

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