Sometimes a city waits for decades to have a huge wooden skyscraper, but all of a sudden two of them potentially come along at once, if a proposed development in central Milwaukee is ultimately approved.
The redevelopment of the Marcus Performing Arts Centre has generated a lot of interest, intrigue and proposals across the state of Wisconsin, but one of the most interesting plans involves building what would turn out to be a record-breaking structure.
Alongside the multi-use performance space itself, an architecture firm has proposed a grand plan for a series of mixed-use buildings to be constructed alongside this.
By far the most ambitious of these and most fascinating to timber frame suppliers is a 55-storey plyscraper that would potentially become the tallest wooden building in the world by a significant margin, as well as the tallest building in the state.
This is an audacious goal, but Milwaukee is used to breaking timber records; the current tallest wooden building in the world, Ascent MKE, is also based in the city.
However, if this building were to be created, it would not so much break the record as completely shatter it, and in the process of doing so revolutionise what is possible with wooden frame construction.
At present, these are just proposals, but here is what is currently known and what it means for the rest of the mass timber industry.
More Than Double
The exact proposed height is not known at present. The proposition is for a project that is 1.2m square feet in total, although this includes the area of multiple buildings and a proposed maximum height of up to 55 storeys.
For comparison, Ascent MKE, which just about took the record for the world’s tallest wooden building from Mjøstårnet in 2022, has 25 storeys and a stated height of 87 metres.
This means that the proposed new building would not only double the current record holder but could potentially be as high as 200m tall, which would be taller than The Scalpel in London.
The only proposed wooden building that would be taller than this is the W350 Tower project in Tokyo, Japan, which would be 350m tall but no further reports have been found on its progress since its landmark announcement in 2020.
The new Milwaukee project is at the same conceptual level but benefits greatly from the fact that the city has committed to wooden construction before with Ascent MKE.
Much like that tower, it would demonstrate a commitment to sustainable construction and finally move away from harmful materials such as concrete, providing a figurative and literal blueprint for other cities and nations to follow.
The Great Unknowns
Whilst it is easy to rightfully celebrate the plan as a victory for sustainability, the details of the plan have not quite reached the general public yet, but the ultimate determiner of the project’s success will be in its details.
The actual final height is currently unknown, in large part because the design has not been finalised. The architect told architecture magazine Dezeen that the concept is likely to “change and evolve” following discussions with the City governance.
There are conceptual renders of a rounded skyscraper with a huge slanted roof box, but at present these renders do not have any solid proposals, design documents or publicly available planning permission to go with them.
The other question, one that is rather important given the location, is the role concrete will have to play in the final building.
Ascent MKE relied heavily on a concrete foundation, two concrete cores for the lift and stair shafts and a six-level concrete podium that acted as an underground car park, making it more of a timber-concrete hybrid building.
It still used significantly less concrete than a non-timber skyscraper of that size would have, but the key to sustainability is to do as much as possible to bring down the use of a material that has a huge carbon cost not only in transportation but also as part of the process of mixing it.
Mjøstårnet also relied on concrete stabs for acoustic and comfort reasons, but to a far smaller degree. Unlike Ascent, all of Mjøstårnet’s structural and floor-spanning elements are constructed from timber, because the concrete was supported by a timber primary structure.
Whether this new building will follow that example or the Ascent model of a concrete core upon which a timber building is constructed, it would still be an astonishing achievement and proof of the capability of timber frame construction from the smallest log cabin to the biggest skyscraper.