Rethinking Modernism: What Can Architects Learn from Philosophy?

Two of our designers have big ideas about reviving mid-century landmarks.

14 min readNov 5, 2020
SOM replaced Lever House’s original curtain wall in 2001 with a state-of-the-art facade that set a new precedent for the preservation of 20th-century architecture. (Photos © Ezra Stoller | ESTO and © Florian Holzherr)

Earlier this year, two members of our New York team contributed an article to Architecture Philosophy, the journal of the International Society for the Philosophy of Architecture (ISPA). In the piece, Frank Mahan and Van Kluytenaar reflect on SOM’s work preserving, renovating, and adapting the firm’s own iconic mid-century projects. The practice of adaptive reuse, it turns out, raises a number of thorny questions: What does it mean to modify an existing building to serve in the present? And what, exactly, confers a building’s historic value?

Nearly 20 years ago, SOM took on the task to replace and restore Lever House’s curtain wall — a delicate operation that required substituting the original materials of the 1952 building, New York City’s first modernist landmark. The seamless integration of a new state-of-the-art facade set a precedent for the preservation of 20th-century architecture. What philosophies have emerged since, and how have they been applied to other buildings? We spoke with the authors to find out more.

Tell us about the dialogue between architecture and philosophy — how has it made you think about your work in a different way?

Frank Mahan: These conversations began when I was invited to speak at the International Society for the Philosophy of Architecture conference, in 2018. The conference took place at one of our recently completed buildings, Polaris Hall at the Air Force Academy. It was quite a different experience from what I’m used to — I thought I would be out of my depth as an architect presenting to a group of philosophers, but they were thrilled to have someone who is building real things in the real world. It turns out we have a lot to learn from each other, and it pushed us hard to think about the way our work engages with history and with the wider culture.

The authors argue that preserving the ideas behind a modernist building, not the actual material, is of most importance. (Image © SOM)

Someone made a connection to Theseus’ paradox, which is interesting to think about in relation to architecture. If the ship Theseus sailed has been so heavily repaired that nearly every part has been replaced, is it still the same ship? Our renovation of Lever House, in which we replaced the curtain wall, gets at a very similar philosophical question: does it still have the same value as a landmark? And our answer — that it’s preserving the idea, not the actual material, that matters — was actually quite a radical shift in terms of how people were thinking about historic preservation at the time. Issues of identifying these buildings as works of art, but also as civic works, came up as well. A lot of SOM’s projects are prominent buildings and public spaces, so everyone who uses them or encounters them has a certain sense of ownership.

Van Kluytenaar: Architectural theory is often written by architects rather than by theorists or critics, and its use of philosophy tends to be somewhat tangential. In our paper, we attempted to be more thorough. We were inspired by the way that art criticism uses philosophy as a lens to view art, and we used that approach to think through these buildings. And it turns out that mid-twentieth century aesthetic theory — Merleau-Ponty in particular in this case — can teach us a lot about how architecture conveys meaning.

In the years leading up to Lever House, the means of production and the economic environment hastened a new kind of architecture, and with that, new meanings. (Photo © Ezra Stoller | ESTO)

Why do you believe postwar architecture requires a distinct approach to preservation and revitalization?

Frank: The architecture of this era was in large part a reflection of its time: rapidly evolving abilities in production and manufacturing; a more widespread use of manufactured materials; a shift from the importance of the materials themselves to the way they are arranged. The materials create and gain meaning by their juxtaposition. The elements of architecture essentially become mass-produced at this time, which is a shift from the inherent quality of the materials previously bestowed by the hands of craftsmen. The means of production and the economic environment hastened a new kind of architecture, and with that, new meanings. Our paper posits a means of engaging with mid-century modern work that’s specific to this period, and is radically different from traditional theories of preservation. We developed these ideas directly from our practice, from engaging with our own buildings over and over.

Van: The opening of Lever House in 1952 ushered in a new synthesis of modernist ideas — the vertical slab and horizontal base, the glass curtain wall, and the public courtyard — many of which soon became staples of contemporary architecture. That same year, Maurice Merleau-Ponty’s “Indirect Language and the Voices of Silence” posited that individual elements of an aesthetic object bestow significance on one another precisely by virtue of their juxtaposition. We’re not suggesting that Gordon Bunshaft was reading a specific theorist like Merleau-Ponty, but rather that certain ideas about aesthetics were bubbling in Europe around the time Bunshaft was there as a Rotch Scholar. We try to show how productive it might be to think through Bunshaft and SOM’s approach to architecture within this theoretical context.

What’s truly important is the concept, rather than the concrete materiality of the space. Your experience of the building is the experience of an idea.

Using Merleau-Ponty as the lens was a particularly rewarding approach, given his oft-cited relationship to phenomenology. Within architectural theory, phenomenology is primarily about the sensory experience of a physical space, an approach that one might associate today with an architect like Peter Zumthor. Instead, we’re using the writings of someone who’s typically associated with space, materiality, and experience, and using it to make the opposite argument — that what’s truly important is the idea and the concept, rather than the concrete materiality of the space. Your experience of the building is the experience of an idea.

Bunshaft didn’t write much at all. What effect did that have on your discoveries regarding his design intentions?

Frank: You can see his intent when you study the buildings. Patterns emerge when you work on as many of them as we have. The plan of Lever House’s ground floor, with its glass-enclosed lobby, marble-clad stair cores, and extended planter, is a masterful modernist composition of elements floating in a field that reminds me of the Air Force Academy in miniature. You can study the relationship of the parts and understand the intent. He was rather explicit about it. The Air Force Academy is not a work of subtlety, but it is powerful.

Van: The lack of writing also makes sense within the argument we’re proposing. What matters is not merely the designer’s intention — what he or she may have said or written — but intention that is made evident in the work itself. In this way the lack of writing forces the theorist to study the buildings and the various relationships among the parts and make a case for how the relationships work and give meaning to the building.

Your paper discusses the importance of storytelling as part of the synthesis of time and place in a successful adaptive reuse project. How do these stories take shape?

Frank: That’s such a compelling part of the process in an adaptive reuse project. You’re working with buildings that have a history, and that makes for additional considerations. You can change an existing building more effectively if you research, understand, and harness the stories it brings with it. You have to understand these buildings deeply in order to craft a new narrative. The idea is not to create change for its own sake, nor to preserve a building in amber, but to breathe new life into it, to make it more vibrant, to make it a contributing citizen of the city again. Storytelling can help create that bridge between past and future.

If you respect the architecture, it imposes more constraints than any regulatory body can.

We’re fortunate that most of the adaptive reuse projects we work on hold a civic and cultural importance. One example we’re working on now is the restoration of the Waldorf Astoria. Even though it’s not a mid-century modern building, we began with the same approach: researching the intentions of the original architects, understanding how the building was executed — which does not always match up with intent — and considering how the place has changed over time. Preservationists often talk about the architect’s intention and original condition, but change over time is also important, and that also involves people who use the buildings. During one community board meeting, people were sharing important personal experiences they had inside various spaces of the hotel; they didn’t want it to change from the way it looked on that day they remembered being there. Those memories didn’t always represent the original vision or the architect’s intent, but they are still valid. You have to give weight to the changes that occur, as well as intent, and then weave them together into a new narrative.

The Waldorf Astoria is rich with stories that are interconnected with the surrounding culture. We found that a lot of alterations took place in the 1960s, as modernism reached its peak. The Waldorf is located where it is because of its proximity to Grand Central Terminal. But as rail travel declined with the arrival of the Jet Age, it was renovated in order to keep with the times.

We want to see our buildings not only respected and preserved, but to be positive contributors to their cities.

Understanding and developing the narrative of a building has turned out to be very important with these projects, and one can take this approach with any adaptive reuse or preservation project. Bringing a narrative or subjective aspect to what is otherwise a series of objective forces is an important element.

Do you come across any confusion during these public sessions regarding the difference between adaptive reuse and pure preservation?

Frank: Well there’s certainly a tension. Even if the building at hand is privately owned, when you’re working with iconic mid-century modern architecture there’s a sense of shared ownership among the public. And among certain groups, there’s an expectation of pure preservation. But we find that in order to effectively reinvigorate historic buildings some changes are often required. The way people use buildings changes over time, so one has to find a balance.

Do clients seek you out because they believe today’s SOM is the best fit to revisit its own legacy projects?

Frank: Sometimes. In those instances they think, instinctively, that we know the work better than anyone else and would want to be involved. We think about this topic of adaptive reuse very carefully. We read contemporary accounts of the projects, we dive into our own archives of sketches, renderings, finished drawings, and client-architect correspondence. Our legacy is an advantage. We want to be good shepherds of it. We want to see our buildings not only respected and preserved, but to be positive contributors to their cities. It does us and those buildings no good if they’re not vibrant, active places.

All of our projects to this day are strongly influenced by our legacy and our way of thinking about those works. The ways we think and talk about all of our projects is in our DNA. There is something about engaging in multiple SOM projects over and over that helps you to recognize patterns that might not otherwise be so obvious.

The original client for 510 Fifth Avenue wanted something adaptable for future reuse. He even showed the designs to a publisher and a department store owner. (Photo © Ezra Stoller | ESTO)

Are there instances where you were surprised by the intent you discovered for a building you were asked to revisit?

Frank: We had an amazing surprise when we were adapting Manufacturers Hanover Trust. When we were brought on for the renovation project in 2011, the building was falling into a state of disrepair and not the right fit for a bank branch anymore. It’s on a very active corner — 43rd and Fifth Avenue — so it deserved new life and we were trying to figure out how to communicate that effectively.

Through our research, we discovered that the original client, bank president Horace Flanigan — what an amazing mid-century name — had experience with bank branches closing after the Great Depression. He explicitly told the architects that he wanted this new building to be adaptable so it could be reused in the future — he even showed the designs to a publisher and a department store owner. That was an incredible epiphany which freed us to propose necessary changes.

The way we navigated change with preservation was to identify what we thought were the primary characteristics of the building. In thinking about original intent, we identified the most important elements — things that defined the architecture — while elements we determined to be of a secondary level of importance were given greater flexibility for changes. We integrated entrances into the building’s east facade, divided the first floor to allow for additional tenants, and rotated the escalators to run parallel with the new partial glass wall. We preserved the glass curtain wall facade, the luminous ceilings, Harry Bertoia’s screen wall, the white marble piers, and the circular stainless-steel vault door.

Key elements at 510 Fifth Avenue were preserved by the adaptive reuse team, including Harry Bertoia’s screen wall, while the escalators were rotated to run parallel with the new partial glass wall. (Photo © Eduard Hueber)

Is there an environmental component to this kind of work? Surely the policies and cultural ambitions around sustainability have evolved since the 1950s…

Frank: Preservation has traditionally been a more culturally-focused endeavor, but connections between environmentalism and preservation are relatively new. Connecting that idea to mid-century modern architecture is even newer. Studies show you can tear down an existing building and replace it with a new high-performance building, but it will still take between 10 and 80 years to overcome the carbon debt created by tearing down the old one.

When you look at the built legacy of the mid-century boom — a massive amount of development all over the world — you can see the potential for an incredible impact. Construction technology that was very innovative at the time is now failing because of its age and changes in construction technology. Now these buildings are typically considered environmentally poor performers. The imperative to revisit mid-century works and rehabilitate them from that standpoint is significant.

Manufacturers Hanover Trust Bank circa 1954 (Photo © Ezra Stoller | ESTO) and circa 2012 (Photo © Eduard Hueber | archphoto).

Even so, we usually find that upgrading an original curtain wall to an insulated curtain wall is beyond the scope of most projects. It’s always on the table but the costs are still prohibitive. New York’s Local Law 97 now mandates energy targets for existing buildings, and failure to comply will result in financial penalties — so sooner or later the economics will make sense. Other cities around the world are introducing similar laws as well.

Van: We thought about the environmental aspect when we entered a competition for Metals In Construction Magazine earlier this year. It asked participants to transform the facade of an aging Manhattan building in order to reduce carbon emissions, contribute to the city’s Green New Deal, and make it financially viable for the owner. We designed a concept for a super lightweight double-skin facade, one that is transparent but with enough opaqueness to handle solar radiation. We also made changes to the massing, carving out sections of the building and putting in terraces — strategic changes that allow the building to develop a whole new life.

Besides Merleau-Ponty, you also look at two 19th-century figures, Eugène Viollet-le-Duc and John Ruskin, and the way they understood architecture and intent in the previous century. How does your approach to adaptive reuse compare to their beliefs?

Van: Ruskin is seen as the godfather of contemporary preservation theory, and his idea was straightforward: preserve the integrity of what’s there, touch it as little as possible, let the decay speak for itself. We’re making a very different argument — that it’s not the materiality but rather the idea that is most important. Viollet-le-Duc is a compelling counterpoint to Ruskin. He believed in fidelity to the original design, in the reestablishment of its original ideas, and that’s a precursor of sorts to modernism’s emphasis on the conceptual. He deemed the structural elements to be the core of a building’s aesthetic value.

The U.S. Air Force Academy conveys a distinct (and landmarked) visual identity. Counterintuitively, its constraints allowed for greater creativity when SOM returned fifty years later to design Polaris Hall. (© SOM)

Frank: Viollet-le-Duc was working with different technological means and research options than we are, but we see common ground between our approach and his. In one sense, our work at Lever House was a very straightforward act of preservation, where you’re replacing things in-kind, as they are. But that’s radical from its own perspective — you’re replacing the materiality of the building but allowing it to carry the same meaning. At 510 Fifth Avenue, there was more speculation, the creation of a new narrative. And at Polaris Hall at the Air Force Academy, there’s a new building stemming from the ideas embedded in the original, surrounding campus.

A model of the Air Force Academy campus, showing the relationship between Polaris Hall (right), Walter Netsch’s chapel (left), and the campus grid. (© SOM)

One might be surprised to see Polaris Hall presented as an example of adaptive reuse. What effect does its presence have on the arrangement of the historic campus?

Frank: Half of the usable space inside Polaris Hall is renovated existing space, so technically it really is adaptive reuse, although formally it looks like a new building. We describe the Air Force Academy as a campus, but it is not like a typical college campus with distinct buildings from different times by different architects. It’s a place unlike any other, photographs don’t do it justice — the consistency of the built form, its scale, the relationship of the architecture to the land. The Air Force Academy was designed at a single time and its buildings are so thoroughly integrated with one another, with plazas and landscapes in a careful composition, that it operates more like a single organism to which Polaris Hall is an addition.

The design intent present throughout the Air Force Academy “is explicit and it allowed us to exercise an extra degree of creativity within the framework,” says Frank Mahan. (Photos © Magda Biernat)

The client asked for something iconic, but that also wouldn’t compete with the existing primary icon — Walter Netsch’s chapel. So how do you create a second icon? There were an immense number of constraints. The grid is literally inscribed onto the pavement across the campus — the intent is explicit, and that allowed us to exercise an extra degree of creativity within this framework. We used the angle to the star Polaris — equal to the latitude at which you’re located — to introduce a diagonal to the orthogonal grid. By simply connecting Polaris to the grid, we created something iconic that related in an abstract way with its diagonals, to the chapel, but still respected and was derived from the ever-present grid.

The Air Force Academy is a protected National Historic landmark district, but the most stringent constraints were posed by the campus architecture itself. It has such a strong identity, such strong concepts, that these clear constraints counterintuitively allowed for more creativity. If you respect the architecture, it imposes more constraints than any regulatory body can.

Frank Mahan is a New York-based architect and Associate Director at SOM. As the leader of a studio within the firm devoted to adaptive reuse projects, he has played a major role in the renovation of New York City landmarks including One Chase Manhattan Plaza (28 Liberty), the Waldorf Astoria Hotel, and the Manufacturers Hanover Trust Company building (510 Fifth Avenue).

Van Kluytenaar joined SOM’s New York office in 2018 as an architectural designer. He is a graduate of the master of architecture program at Princeton University.

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