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The US city of Milwaukee is already home to the world’s tallest timber tower. But another, even taller, wooden skyscraper could be added to its skyline, designed by Vancouver-based studio Michael Green Architects (MGA).
The firm recently released plans for the development, which includes a 55-story tower made principally from mass timber — thick, compressed, multilayered panels of solid wood. If built, it would usurp the current world title holder, the 25-story Ascent tower by Korb + Associates Architects, as well as becoming the tallest building in the state of Wisconsin.
MGA, which specializes in wooden architecture, hopes that the project will set a “new global benchmark for mass timber construction.”
The project is part of the redevelopment of the Marcus Performing Arts Center, which opened in 1969 and won the Honor Award for Excellence in Architectural Design from the American Institute of Architects in 1970. Led by Neutral, which bills itself as a “regenerative development company,” the redesign will transform what is currently the center’s concrete parking lot into a space with residential units, offices, restaurants, cafes, grocery stores and public plazas. According to MGA, construction will cost an estimated $700 million. The plan is currently going through the city’s approval process, during which it is expected to evolve.
While the use of mass timber is steadily increasing worldwide, thanks to changes in building regulations and shifting attitudes towards the material, it has yet to match the sheer height of buildings made of concrete and steel — although a slew of timber high-rises have been proposed in recent years. MGA says its tower design would be approximately 600 feet (182 meters) tall — more than double the 284 feet (87 meter) tall Ascent tower.
“The race for height is important,” said Michael Green, an architect and founder of MGA. “It’s not about showing off, it’s about showing what’s possible to the public.”
He argued that the reason timber skyscrapers haven’t yet become mainstream is because climate change hasn’t been at the center of the conversation. “We didn’t really need to challenge the status quo of steel and concrete,” he said. “But because those materials are so hard on the climate, we had to find a different way to build towers and big buildings in general.”
Currently, the building and construction sector accounts for 37% of global emissions, much of it down to the production and use of materials such as concrete and steel, which are massive carbon emitters. Trees are the opposite, absorbing carbon throughout their lifetime. If those trees are turned into mass timber and used for construction, that carbon is “locked in,” or sequestered for however long the building stands. “By building with it, we’re actually building with a carbon sink,” Green argued.
But he admits that sourcing enough sustainable timber at the scale needed to build our cities could be a challenge. Indeed, some studies warn that increased demand for mass timber could increase pressures on land use.
To deliver its purported carbon savings, trees must be grown for a significant length of time to sequester carbon and be replanted once they are cut down. Green said that MGA uses wood from responsibly managed forests in North America.
Long term, he believes that to counter supply issues, architects will have to think beyond wood, adding that MGA is currently working on creating other plant-based construction materials. However, he contends, if we want to ease off concrete and steel, mass timber “is the best option for today.”
Other barriers to using mass timber have been both cost and strict building regulations. But in recent years, this has changed, explained Green, with mass timber now cost competitive with concrete and steel in many regions. “There are more manufacturers available than we had before: now we’ve got a big competitive market and it’s still growing,” he said.
Building codes have also evolved, with some countries in Europe mandating the use of wood construction as part of their climate objectives. In the US, the International Building Code updated its policy on mass timber in 2021, allowing mass timber buildings of above six stories.
The city of Milwaukee has been particularly forward-thinking, said Green, encouraging development within the city center while also being willing to experiment with new materials. The proposed tower will still use concrete foundations and steel components to make up the elevator cores, but he estimates wood will make up about 90% of the building material.
“It is America’s second-scale cities that are breaking new ground on innovations that will help manage climate change,” he said.
His hope is that the Milwaukee tower will help to push innovation in climate-friendly architecture, and open people’s imaginations to building with timber.
“We need breakthrough moments, and this is a breakthrough moment,” Green said.
