Milwaukee: Prepare to enter the record books.
Ascent, the second of two mass timber structures in the city, will open to residents on July 15, 2022.
But unlike Milwaukee’s first log structure, Timber Lofts at Walker’s Point, this $80 million building will rise 25 stories – 284 feet – making it the tallest log building in the world, eliminating the Norwegian tower Mjösa from the first place.
Located at 700 Kilbourn Avenue in downtown Milwaukee, the 259-unit building will offer one-bedroom (starting at $1,715 per month), two-bedroom (up to $4,450 per month) and three-bedroom apartment (up to $7,860 per month) .
After:A 15-story apartment project in downtown Milwaukee that will use massive wood construction plans a first grand opening in the spring
After:The construction of an unusual apartment tower in downtown Milwaukee, the hardwood Ascent, has reached a key milestone.
Compared to typical high-rise buildings — which are constructed of concrete and steel — structures like Ascent use treated lumber straight from trees.
And like the forests they come from, log buildings actively remove carbon (CO2) from the atmosphere, locking it inside the structure for as long as the building is standing.
Moreover, log buildings are not only healthier for the planet; they are also healthier for their inhabitants. Studies suggest that just being in a room with exposed wood reduces stress — an effect that appeals to our “biophilia,” or the innate desire we have to be surrounded by nature.
Milwaukee enters the global dialogue
Alex Timmer, an assistant professor at the University of Wisconsin-Milwaukee School of Architecture and Planning, said a log building like Ascent puts Milwaukee in an unexpected spotlight.
“The conversations that are happening right now around wood are happening on a global scale,” Timmer explained. The most notable mass timber structures are found in Europe, so it is unusual for a building of this type to be constructed in Milwaukee.
Ascent will serve as a test for future technological advances in architecture. Rather than asking, “How does a building like this happen in Europe?
Assessing how Ascent performs in our city will potentially open the door to more conversations about hardwood as an industry as a whole – rather than as a single example in a city, state.
Construction is consumption
Timmer and a team of collaborators from Rivion, WoodWorks and the Forest Products Laboratory are currently working to collect data on Ascent’s life cycle, an effort that measures the building’s total environmental impact.
Timmer explained that they were analyzing Ascent’s “embodied carbon” and “embodied energy” — measures of how much energy was needed to create the building and how much carbon was produced during construction.
“Architecture is almost purely consumption – it consumes energy,” which, in turn, releases carbon, he said.
It is important to take this into account whenever a new building is constructed.
Experts estimate that demand for new housing will double by 2060, requiring 2.4 trillion square feet of new housing – the equivalent of adding the entirety of New York City to the world each month during the next 40 years, according to the 2021 Global ABC Global Status Report.
This same report indicates that the construction industry accounts for 47% of global CO2 emissions each year. And about 22% of global CO2 emissions come from the two biggest offenders in construction: concrete and steel.
“Embodied carbon is most important to us as architects because it has the most immediate impact,” he said. We can change the way we construct new buildings, transforming the industry into an industry of reuse., reduction and sequestration.
It starts with solid wood.
Solid wood is a “no-brainer”
Solid wood structures deal directly with embodied carbon because they involve considerably less on-site construction. For Ascent, the construction process was estimated to require 90% fewer vehicles and 75% fewer workers to complete the work, which was done in a quarter of the time, according to the building’s website.
Log buildings not only reduce embodied carbon, they also pull CO2 directly from the atmosphere and store it in the structure for decades.
According to CD Smith Construction Co., the company contracted to build Ascent: “An 18-story log building has a negative carbon footprint equal to taking 2,350 cars off the road a year.”
“Solid wood is definitely one of the really, really important tools that architects have at their disposal right now,” Timmer said. “It’s obvious.”
Responsible and sustainable wood sourcing
With mass timber structures, much less steel and concrete is used, making them “greener” than typical skyscrapers.
This does not mean that these materials are completely absent. Steel and concrete are still needed for Ascent’s foundations, parking lot, pool, stairwells and elevator shafts.
This is part of the trade-offs that exist when designing any structure. As Timmer explained, a building is rarely made from a single material; functionality should be a factor.
“You’re not going to build a massive wooden swimming pool, are you?” he said. “What’s great about embedded carbon (addressing) is that it allows you to make an informed choice about the material you use.”
Timmer explained that it is important to research Forest Stewardship Council standards before purchasing any wood product. This group has standardized measurements that identify whether a material has been harvested sustainably.
“As good as solid wood can sequester carbon, if you destroy a logging operation to produce it, you prevent it from being a sustainable product,” he said. “As long as these trees are sustainably forested, sustainably harvested, we potentially have a renewable resource and we can sequester more and more embodied carbon.”
Ascent Redefines Building Codes
While solid wood represents a future for sustainable architecture, building codes have not kept up with technological advancements.
Timmer explained that current US building codes prescribe the safety standards that a building must meet. These mandates originally prevented Ascent’s height-to-timber ratio due to fire safety concerns.
Ascent has been exempted from this code by doing things differently: providing performative measures, rather than prescriptive those.
The developers have shown that when solid wood burns, it only burns on the outside, creating a “charred zone”. This charred area protects whatever is inside, keeping the structure intact. “It’s totally safe,” he said.
Using the example of Ascent, Timmer predicts that we will see building codes evolve and become more sophisticated.
“We’re going to get better at constructing buildings and we’re going to understand them better,” he said. “That means we can ask more of this particular building typology, and we can ask more from an environmental point of view.”
Building a structure like Ascent is part of an experience that comes with building any building, Timmer said. “You learn a ton through the building process. Even though we do an immense amount of lab testing on these materials, it’s the actual construction, the actual building that teaches you.”