Buildings have always been designed for a particular use, whether it’s office, industrial, retail, or residential. But now, in a time where architects and developers are feeling the pressure to think outside the box and further into the future, a new use concept has emerged that some in the commercial real estate industry believe could become a new standard for building design.
The neutral-use building is a concept that has been floated by a handful of architecture and engineering firms and is essentially a building designed to be able to adapt to different uses over time. These buildings are also engineered to last much longer than traditional buildings, giving them plenty of time to reinvent themselves. The term has gotten a lot of attention lately thanks to a recently proposed a neutral-use building concept called the unTower, a donut-shaped skyscraper with systems and structural elements that can be adapted to different uses over time. Potential uses could include a residential building, office space, a hotel, and even a hospital.
The impetus for the project came from a couple of different directions. One was the need for more sustainability and resiliency in development, especially as the country and the world are working to decarbonize buildings significantly in the coming decades. The other was the need for flexibility and adaptability in today’s real estate market. More than just the massive shift in office space needs since the pandemic, plans can frequently change from concept to opening in the development process, which can lead to costly delays. The neutral-use idea promises to streamline the construction process, lower operating costs, and add value to the property through its biophilic design elements, unique design, and high level of energy efficiency.
The unTower proposal was authored by Matthias Olt, Principal in Architecture at Toronto-based IBI Group, and Jill Jago, Director of Advanced Strategy at B+H Architects. They also worked with the engineering firms Coffman Engineers and Robert Bird Group on the design concept. In working on the proposal for unTower, the team researched two sites in particular that would work for design and cost, one in Bellevue, Washington, and another in Burnaby, British Columbia. While they based their study on sites in North America, the team said its analysis can be applied to places around the world.
The cylinder-shaped tower has some distinct design elements. Instead of being built within the interior of the building, the elevator core is external and infrastructure is vertical. Modular, prefab and mostly reusable building components are used in the building’s construction, with floor plates stacked and open to both the interior atrium and the building’s exterior. By layering the floor plates, the design allows for structural and systems efficiencies, easier modular construction, and fast-tracked manufacturing, according to the proposal. In forming the design of unTower, the team took inspiration from emulating modular structures including Japanese temples that have stood for more than a thousand years. The adaptable concept can be built at a competitive cost and would be a good match for cities with rapidly expanding development and where sustainability and resiliency add value.
At its core, the architects’ neutral-use concept ticks off a lot of boxes that developers care about right now. There’s sustainability, faster construction timelines, and much less embodied carbon, since the structure wouldn’t have to be torn down after a certain number of years. It also helps address the mammoth amount of development that is expected to take place over the next several decades. “Between now and 2060, the world will build an entire New York City every month for 40 years,” the team wrote in the unTower proposal. So far, the group’s proposal has drawn interest from some major commercial real estate developers, including Tishman Speyer and Hines.
While the concept seems like just the kind of thing that many developers and potential tenants would be interested in, not to mention cities looking to welcome sustainable development and cut down their carbon footprint, not everyone is on board. Jessica Martinez is a sustainability specialist at the structural engineering firm DCI Engineers. In her work, she leads internal staff education, research and development surrounding embodied carbon and life cycle assessment. Her firm has been focusing on reducing the carbon footprint of structural designs, and part of that is looking at the future. She has seen some attempts at neutral-use building, including some projects her firm has done where they designed single floors that were neutral-use. One of the difficulties she sees with something large-scale like the unTower is how to design mechanical and electrical systems that would work for different uses. “It seems like it’s quite the puzzle,” Martinez said.
From a structural standpoint, the biggest difference Martinez sees is in how much weight a building can sustain, or occupancy loading. Office buildings typically have higher loading needs than residential buildings, due to the number of people on a floor at any given time. Another consideration is vibration. If equipment is put on floors of a neutral-use building it could impact the functions of, for instance, life science tenants. On one of her firm’s projects in Seattle, they built a neutral-use floor that had to consider increased loading in the future, vibrations and other impacts that come into play. “It’s very difficult to do everything,” said Martinez about the neutral-use concept. “But at the end of the day, I’m glad we have people in the industry putting out big ideas so we can start having conversations like this.”
Kim Rosseau is a designer in the Atlanta office of global architecture firm Perkins & Will. Her firm has worked on healthcare buildings that were designed to be able to switch from a typical hospital to an acute care facility, but a neutral-use building is something she sees as difficult to pull off. “I think the trend could be designing a building to fit a couple uses in the future but to have a curly, one-size-fits-all building is challenging,” Rousseau said, pointing to starkly different requirements for life sciences facilities versus residential buildings. However, given how the pace of change these days continues to accelerate, the industry should be prepared to face the fact that buildings need to be able to adapt to the way society changes, she added.
While there is certainly skepticism about the neutral-use concept, the unTower seems to have an answer for a lot of the questions raised about it. According to the proposal, the building is designed to be able to scale horizontally as well as vertically and the number of towers and variations in building heights can be done with minimal design changes. Mechanical systems are able to be easily accessed and modified based on tenant needs, modular partition walls can be moved as tenant needs change, and the building’s in-floor composite beam system enables reduced floor-to-floor ceiling heights.
The emerging neutral-use concept promises lower embodied carbon and a longer life cycle, among other things, and can adapt to different uses over time, something that aligns well with today’s shifting real estate needs. Neutral-use buildings are still a new concept, and haven’t yet been built at a large scale, so there hasn’t been a chance to study a neutral-use building for a long period of time and see if it keeps the promises it makes. There are legitimate questions about how the structural and systems design can adapt to any kind of use without major–and costly–changes, and perhaps more importantly, if developers and tenants will be interested in this kind of development at all. Nevertheless, it’s an exciting step forward for the kind of innovative development that if the current times have shown us, will surely be needed going forward.