Amid rising surface temperatures and an ongoing climate crisis, scientists and architects alike are working hard to think of creative ways to reduce carbon emissions when it comes to the building sector – which is responsible for roughly 37% of total greenhouse emissions, according to the World Economic Forum. This in part has manifested a rise of mass timber projects across the globe.

Mass timber is a type of engineered wood product made by bonding smaller pieces of wood together with adhesives or fasteners to create larger beams. Unlike steel and concrete, mass timber weighs less and can be a more sustainable source of building material due to its natural regenerating capabilities, global abundance and design versatility.

“We’re looking for solutions to reduce our carbon impact and timber, wood, is the lowest embodied carbon product,” James Donaldson, a partner at Elysian Park-based architecture firm Johnson Fain, said. “And if you can reduce the embodied carbon of a building, you’re forever locking down its carbon footprint.”

The most common type of mass timber products is cross-laminated timber, or CLT, which is made by gluing layers of kiln-dried lumber together at right angles.

While different forests are home to different types of lumber, most North American mass timber is constructed in the Pacific Northwest – where the common species include fir, spruce and pine wood – each of which differs in its appearance and performance characteristics, according to Gensler.

The material is relatively new on the market but, given its environmental benefits, has piqued global interest – with Norway, Canada and the Netherlands leading the curve. The United States has also seen a rise of mass timber projects, including a handful in Los Angeles that opened this past year and several more underway.

Local interest

Chinatown welcomed one of the first and largest hybrid CLT buildings in Los Angeles, 843 N. Spring St., when developer Redcar Properties Ltd. unveiled the five-story property in August. While technically a renovation project, the project spans 145,000 square feet and serves as a mixed-use office and retail property.

It utilizes steel, concrete and mass timber – by combining three- and five-ply CLT panels and concrete topping slab with exposed steel columns – which is common for many mass timber projects of scale.

“We thought a hybrid structure made a lot of sense because we’re connecting it to a concrete structure and also this is one of the first and largest projects of its type in Los Angeles,” Thomas Robinson, founder and principal of Portland-based Lever Architecture, which designed the Spring Street project, said. “It’s a new material to the city so we wanted to just be sort of thoughtful about how we introduced it and make sure that it’s going to meet everyone’s expectations.”

Lever was responsible for designing America’s first ever domestically sourced CLT project, Albina Yard, an office building in Portland which was completed in 2016 and serves as the firm’s own headquarters.

42XX, which opened in October, has since taken the title of Los Angeles’ biggest mass timber project yet. Spanning three separate buildings and more than 150,000 square feet, 42XX is a creative office campus in Marina Del Rey developed by local developer The Bradmore Group and designed by Rios.

It, too, utilizes concrete and steel framing, but the mass timber hybrid approach cut the structure’s weight by half and offsets carbon emissions equivalent to removing 262 cars from the road for a year, according to Rios.

And a smaller mass timber project that opened this past year was SuperBungalows on Marathon, a nine-unit multifamily complex in Silver Lake, where one-bedroom units start at $4,250 per month and two-bedroom units at $6,750 per month.

The building was designed and developed by SuperLA, a full-service real estate startup founded in 2020 with the mission of reinvigorating the environment. It marks the first multifamily building made with CLT to be completed in Southern California.

Sustainable benefits

One of the biggest drivers behind mass timber’s rising popularity lies in its environmental performance.

The average residential home has an embodied carbon value of 184 kilograms of carbon dioxide per square meter of conditioned floor area, with a typical residential building reaching 600 kilograms per square meter across its life cycle, according to a 2023 report by Rocky Mountain Institute. That means a significant portion of a building’s carbon footprint comes from the materials used to construct it, not just its operational energy use – and those figures don’t even account for commercial structures.

Mass timber, on the other hand, is a renewable resource that sequesters carbon dioxide as it grows, making it a more sustainable alternative to traditional building materials like concrete and steel.

Although timber needs to be harvested, the material is renewable so long as trees are replanted, which allows for the growth of more CLT and offset of impact. And when a tree is harvested, that carbon remains stored in the timber for the duration of its life, making it a carbon sink.

“Concrete is among the highest carbon producing materials in the built world in terms of carbon dioxide and greenhouse gases,” Mark Motonaga, creative director and partner at Rios, said. “By making the right choices, we can start to intentionally minimize and reduce our impact on our carbon footprint of the building. And it’s a ripple effect.”

Beyond its repository features, the lighter build of timber calls for less materials needed and quicker timeframes. And since CLT panels are engineered at manufacturing facilities prior to being brought on-site, this in turn can lead to greater efficiency and faster builds, which can be vital for some markets, such as housing, which is lacking in supply.

Biophilic design

Another significant draw in using mass timber comes down to aesthetics.

“Once you’re inside a space that’s built out of mass timber, it just feels different,” Aaron van Schaik, founder and principal of SuperLA, said. “A lot of that has to do with the biophilic benefits of timber, having exposed timber inside the home.”

Biophilic design is a design philosophy in architecture that connects people with nature in built environments. It’s long believed that natural elements, such as timber, plants, water and light, can foster wellness when left exposed by improving occupancy health, wellbeing and productivity, as well as boost creativity and cognitive performance.

“We’ve never lived in homes that are currently being built today, like white boxes with steel finishes and artificial down lighting and gray flooring, that’s not where humans have evolved and lived,” Van Schaik added. “There’s lots of studies on biophilic benefits of timber and how that makes people feel, but I think it just comes down to our need and desire to be reconnected with nature.”

Especially potent amid office challenges as remote work treks on, many experts agree hospitality aesthetics stand out in office settings and mass timber might just be the key employees need to be enticed back.

“From a wellness standpoint, and a connection to what people want, they want to feel like they’re in a less corporate, less commercial environment after the pandemic or coming out of work from home,” Motonaga said. “You’re used to a certain level of informality, a little less buttoned up, tight environment. And so having timber is one way to introduce a level of that warmth of what I would call ‘imperfect perfection.’”

Natural disaster resilience

Despite being nimbler than concrete and steel, mass timber remains highly resilient when it comes to protecting against natural disasters.

When it comes to earthquakes, for example, mass timber structures are generally considered to have improved seismic performance due to their lightweight nature which reduces seismic forces on their foundations and instead distributes them.

“Timber in general can move and bend, whereas concrete cannot,” Motonaga said. “Concrete is about resisting movement. Timber wants to move so it’s really built to move in an earthquake. And that’s where the code exists, it either wants it to be super stiff or it wants it to be super malleable, and timber can do the very malleable.”

And while we’ve seen wildfire destruction sweep Los Angeles over the past week, experts point out that timber burns slower than steel and concrete due to its self-charring behavior, making it inherently more fire-resistant than its counterparts.

“Mass timber is designed with what they call a char layer…let’s say you need 10 inches of structure to make sure that the building is structurally sound, they build it with a deeper layer. They’ll build it 14 inches or 16 inches deep so there’s a 4- or 6-inch char layer,” Greg Skalaski, executive vice president of Boston-based Shawmut Design and Construction’s West region, said.

Shawmut was the general contractor of 843 N. Spring St., one of nine current and completed mass timber projects for Shawmut, but its first on the West Coast.

“The mass timber is so dense, and the lamination is also not combustible, that it takes a long time,” Skalaski added. “God forbid there is a fire there, and (assuming) you have fire suppression systems inside the building, you have time. You have significant amount of time being something could be really affected on the structure.”

Still a novelty

But despite the numerous benefits of mass timber, the biggest challenges seem to stem from it being relatively new.

North America lags in CLT abundance to Europe, said Robinson, who stated that while the United States plays catch up, the material can take longer to streamline due to governance unfamiliarity – which impacted the Spring Street project.

“The city of Los Angeles at the time really was trying to understand building code and how it applied to mass timber, and they actually required us to do a full structural slab (of concrete) on top of the CLT,” Skalaski said. “It’s not that it defeated the purpose … (but) we lost some of the benefits because of the way that the city was asking us to do it.”

Besides the city’s own nescience, architects expressed the learning curve across all parties and emphasized the need for a good general contractor as most of the material risk falls on the development and construction side.

“I like the prefabrication,” Skalaski said, arguing mass timber is safer for his team to build than other construction materials due to the way that the beams are engineered prior to installation. “It is awfully dangerous in general for skilled workers that are spending all their days, all day long, up on corrugated metal panels that have rebar all over. It’s a massive trip hazard; people can get hurt. CLT comes in, it stacks, it’s down, you tape the joints and it’s this perfectly flat wood floor basically. It’s safer from that perspective.”

Rather, the biggest thing holding developers back from mass timber tends to be its hefty price tag, estimated to have 26% higher front-end costs than its concrete alterative, according to the U.S. Department of Agriculture, although this rate will likely decline as the material becomes more mainstream.

But in the case of all three developments, the decision to spend those extra bucks was worth it, explained as a long-term investment for their future.

“We buy and hold our real estate, so we don’t just like buy and flip and sell,” Ali Conwell, project manager at The Bradmore Group said. “We wanted something really special, and we felt that mass timber was that special element that would create a unique, lifelong, timeless building.”

More projects underway

While mass timber can technically be used on any project, Robinson said the sweet spot lies in mid-rise office and density housing projects.

“As we become more sophisticated and understand more about the technologies, you’re going to see more high-rise buildings,” he said. “But I think we’re still sort of in the early stages, and we want to make sure that whatever we’re doing will perform both in terms of structure but also in terms of fire.”

SuperLA is currently working on another mass timber multifamily project in Silver Lake, SuperBungalows on Hyperion, which will be a slightly bigger, 15-unit plus coworking space development, with the same structural integrity as its first, as well as launching a mixed-income mass timber housing line called NiceOut, with its inaugural project set to begin construction in Larchmont next year.

In Baldwin Hills, New York-based Lendlease in partnership with Australian super fund Aware Super is building Habitat, a 454,000-square-foot giant mixed-use development set to include a six-story, 250,000-square-foot office building which will include mass timber technology.

“I hope it catches on with other developers and things like that but, at the core of it too, I think we just need to build better product as a whole,” Van Schaik said. “Sustainability is really important, and I think that should just be expected and mandatory…greenwashing is a big problem I think in our industry as a whole.”

While Shawmut and Lever aren’t working on any current mass timber projects in Los Angeles, the two have their hands full with other mass timber projects across the country.

“I hope it just demonstrates that you can build at scale with mass timber, and you can build with beauty in mind,” Motonaga said. “I think there’s a lot of fear over the financial payback of it and is it valuable enough to justify the premium and all that…when you love something and there’s a demand for it, people will provide it. We need to create these buildings and these environments that generate buzz and generate that connection to the user because that’s what our clients are gauging.”