Has there ever been a more prolific and consistent architectural talent factory than Rem Koolhaas’ Office of Metropolitan Architecture? Over four decades, the studio has launched the careers of a whole generation of today’s most influential and skyline-shaping designers; among them Zaha Hadid, Jeanne Gang, Ole Scheeren, Bjarke Ingels, Winy Maas, Jacob van Rijs and Fernando Romero.

The American architect Joshua Prince-Ramus is another member of this illustrious club, who, like the others on the list, also decided to step out from Koolhaas’ formidable shadow and go it alone. Unlike them, though, he has kept a relatively low profile. The 30-strong practice he leads does not bear his name and he fiercely rejects the ‘starchitect’ label.

“Architecture is not created by individuals”, he once told a room of journalists. “The genius sketch is a myth. Architecture is made by a team of committed people who work together, and in fact, success usually has more to do with dumb determination than with genius.”

Whatever its roots, Prince-Ramus has had no shortage of successes. Entrusted to establish OMA’s first New York branch at the start of the millennium, he led projects such as Seattle’s acclaimed Central Library and the Guggenheim-Hermitage Museum in Las Vegas. In 2006, he purchased Koolhaas’ stake in the office and renamed the company REX Architecture.

Over the last decade the burgeoning studio have completed a couple of elegant buildings, including the Dee and Charles Wyly Theatre in Dallas and the Vakko Fashion Center in Istanbul. Now they are preparing for construction to begin on their biggest project to date: a theatre for the World Trade Center campus in New York.

The Ronald O. Perelman Performing Arts Center – named after the financier who is largely funding the project – has been conceived by developer Silverstein Properties as “a prime cultural and social destination to redefine Lower Manhattan.” The centre will host performances of theatre, dance, music, opera and film across three auditoria when it opens in 2020.

The brief called for a building that “defies experiential expectations” by celebrating artistic endeavour and risk-taking. Prince-Ramus admits it’s the most important building he’s worked on to date, both personally and professionally.

“I lived four blocks away from the World Trade Center on 9/11,” he tells me from his office in New York. “That day had a profound impact on all our lives, and certainly for anyone in the city who saw it. I lost everything. The windows of my apartment blew out, and everything was covered with three feet of soot that basically turned into concrete through the humidity and the rain. It was months before I could go back.

“I’ve since moved another four blocks further away, but my daughter’s elementary school is still very close,” Prince-Ramus continues. “So for me being a part of the rebuilding and reassertion of optimism in the city is an honour and a dream. I never would have thought I’d be given this opportunity.”

Designing from the inside out
Situated just north of the two enormous waterfalls and reflecting pool that form the 9/11 Memorial, and adjacent to Santiago Calatrava’s spiky white Transport Hub, the Perelman Performing Arts Center will appear like a monolithic “mystery box” – a structure designed by REX to be simultaneously simple, sculptural and symbolic in equal parts.

The cube-shaped building will be wrapped in translucent veined marble and laminated within insulated glass, allowing natural light to illuminate the interiors during the day, and transforming the building into a glowing lantern at night – the silhouettes of the human movement subtly reflecting the creative energy within. An angular slice cut out of the block will forms a suitably dramatic entrance to the lobby, restaurant and shape-shifting performance halls inside.

I ask Prince-Ramus how his team arrived at the design concept for such a politically and emotionally sensitive project.

“The very first credo of the office is that we believe that architecture should do things, not just represent things,” he says, “so we started from the inside-out, and the mystery box form is a result of the complex interior organisation. We also felt that designing something simple and elegant was appropriate given the importance, sobriety and emotional component of the site; this was not a moment to be precarious. In that way the design evolved from a beautiful confluence of things.”

At REX, like OMA, the process of design is as much a philosophical pursuit as one that is grounded in the practicalities of bricks and mortar. Online they describe themselves as a think tank rather than an architecture practice, and speaking to Prince-Ramus, himself a former philosophy student at Yale, you get the impression that all the sketching and model making is complemented by long and searching debates.

“If you can’t argue an idea, you don’t yet own it,” he says at one point. “Until you can articulate it verbally, in writing or in a diagram, you don’t have it, you’re not in command of it and you don’t have rights to it. This is true in philosophy, in linguistics, in psychotherapy, in a lot of intellectual pursuits. We very much believe in creating arguments for our architectural projects.”

To achieve this, project architects are encouraged to cast away their weaker ideas, return to the stronger ones and tweak them and tweak them until finally the right answer is found. “It’s a very Darwinian process,” he admits.

“The trick is we never rush into conventions and we like to suspend disbelief. If you allow yourself some critical naïveté, something that you’ve never seen before can come out of the investigation.

Sometimes there are steps in the wrong direction; we’ll get fairly far down an evolutionary tree and realise that we need to go and climb back up the tree and take a different branch. In that way a project taking shape is not a linear development but a slow congealing of a narrative.”

Interior innovation
The fruits of all this trial and error can be seen in the Perelman Center’s 8,400sq m (90,000sq ft) interior spaces, where Prince-Ramus says the real innovation is happening.

The three auditoria – individually seating 499, 250, and 99 people if left unaltered – and a rehearsal room can be merged together in 11 different arrangements. Within this, an almost limitless number of stage-audience configurations can be set up. The front- and back-of-house circulation is flexible too, allowing for the various mergings and creating diverse entry, intermission and exit visitor processions. The result is a venue that can host shows of almost any type, scale and size.

“We really want to expand upon what we’ve dubbed the ‘multi-processional’”, he explains, “meaning that the artistic director should have the ability to control not only the theatre dimension, the theatre proportion and the theatre stage audience configuration, but also the sequence by which people enter the building and go into the auditorium, the sequence by which they have an intermission and the sequence by which they meet after a show. They don’t just have control from when the lights start to go down. In fact, they could even script your experience from the moment you book your tickets.”

As I ask how this will work in practice, his voice rises in excitement as he answers.

“They could ask you to do something on the day of a show. They could ask you to wear something. They could ask you to enter the site in a particular way. They could ask you to come by subway. Heaven knows what they could do. They’ll create an atmosphere of suspension of disbelief before you even enter the theatre.”

But the brief called for more than just extreme physical adaptability. Prince-Ramus believes the technology integrated into the building could one day make futuristic concepts – such as holographic actors or performances that are projected simultaneously on stages across the world – a reality.

“If we do our job correctly, as much as our hand will be present, the thrill will be if you see artistic directors going crazy; doing things and conceiving of things that simply had never been done before,” he says. “That’s what totally jazzes me up.”

Balancing budgets
The challenges of designing and building a structure that can constantly transform itself are vast, and REX are working in close collaboration with British theatre consultancy Charcoalblue and executive architect Davis Brody Bond – who created the World Trade Center’s memorial museum – to ensure every single interior configuration has perfect sightlines and acoustics.

Then come the logistics of building one of the last components of Daniel Libeskind’s huge World Trade Center masterplan, in which the obligations from around the site can’t be ignored. Prince-Ramus summarises the obstacles thus: “We’re negotiating the perils of designing a super high performing arts facility on top of a subway station, a PATH station, a subterraneous loading roundabout that services all of the surrounding buildings and a huge vehicular spiral going down from our building.”

All things considered, few eyebrows would be raised if the project goes over budget. Prince-Ramus, though, is adamant that this won’t happen: “We’re not a firm that sees a budget as an obstacle to get around. It’s simply part of the reality of the project – like gravity. There are no excuses for being careless.

“The irony is that if you accept a budget and limitations, and take it on early, it forces clarity, which increases the potential for the project to be extraordinary.”

His concern for financial sustainability won’t end when he hands over the keys. “You know, it’s become harder and harder to raise money for operational budgets, while it’s generally much easier now to raise money for capital budgets,” he says. “You don’t see corporate sponsorship and donors generally giving enormous amounts of money to the 2014 season of The Met. They want to give money for the redevelopment of The Met.”

As a result, he argues, theatres don’t have the operational budgets to transform their performance spaces in imaginative ways. The staging you experience on your first visit will remain unchanged the next time you go. That’s something REX are trying to change. “If you can build flexibility into the building at the start, you guarantee a level of invention that is available to an artistic director. The challenge is to do it in a much more nuanced way than simply handing over an empty shell.”

Spurning starchitecture
As the Perelman Performing Arts Center advances, Prince-Ramus can expect more time in the spotlight as REX’s most visible representative, meaning he’s in danger of being branded with the ‘starchitect’ label he rejects. How does he see himself, I ask, if not the stereotypical ‘lone genius’ the media likes to portray?

“My role in the office is often as a critic,” he replies. “Like everyone, when we’re having debates about the project I’m putting forward ideas, and it just so happens that I’m probably the most experienced in our methodology and therefore probably have a proclivity to argue my way more often than others. But frankly I don’t care where the ideas come from.

“We had a problem once, years ago, on a project and we couldn’t solve it. We debated and debated and we still couldn’t work it out. Then, we came back in the morning and the model had been changed and it had solved the problem. I asked who did it, and no one knew. Eventually, the cleaners came to our office manager and apologised profusely because they’d knocked the model over and broken it. That just goes to show that a great idea can come from anywhere.”

This anecdote raises another philosophical question. If a design can be formed at the point where blind chance and intellectual rigour meet, surely an infinite number of potential solutions to any design challenge could emerge. So how can you know when you’ve arrived at the best answer?

Prince-Ramus’ answer is a simple one: “Beauty,” he says. “We take that very seriously.”

It’s a belief that has informed all of his work, and he’s reminded of it every day by the EE Cummings quote tattooed on the underside of one arm: “Always the beautiful answer who asks a more beautiful question.”

“If there are many possible exceptional solutions to any given set of problems, we always choose the one that is most beautiful,” he says, “and we reject the idea that form and function are two things at odds. We just see that they are two things. They don’t need to work against each other.

“My hope is that when the Perelman Center opens, it’ll be a really extraordinary tool for the creation of new art. But it’ll also be very beautiful. With this building, we won’t have an alibi if it isn’t exceptional.”