Photographs © Louis Kahn Project; Harriet Pattison (left and middle)

Filmmaker Nathaniel Kahn’s most recent project, My Architect, is a feature-length documentary about his father, the architect Louis I. Kahn. Conceived as a journey of filial discovery, it is both a moving tribute to a great artist and a candid portrait of a complex, elusive man. The film premiered last March at the 32nd New Directors New Films festival in New York City and is being distributed theatrically in the U.S. by New Yorker Films; it will open at the Film Forum in New York on November 12 (for more information, including a schedule of screenings around the country, go to www.myarchitectfilm.com).

Q: What did you learn about your dad from making this film?

My father died when I was 11. My early vision of him was based on my experience as a little boy and was very limited. I remember a warm and loving man, but I also knew he had a bigger world, from the amazing stories he told me about it: of India and Bangladesh, of tigers, of people who built buildings carrying baskets on their heads. For a child, it was intoxicating. But in making my film, I discovered much that I didn’t know before—about his struggle, his persistence, his conflicts, his achievements. He went from being a mythological character to being a man.

Your dad had a very unconventional personal life, which he kept secret. Do you have any misgivings about revealing it?

My film shows that I have great respect for my father, but I also have questions about the choices he made.

I tried not to judge him. As he said, “You can be critical of someone, but you should never judge them.” My father was a great mystery, and I didn’t want to dispel that but to examine it. That’s why I designed the film as a journey: You end up with a multifaceted impression of Lou Kahn that preserves his complexity.

What were the challenges of filming your dad’s buildings?

The big challenge was, how do you get the emotional power of these buildings into a movie? I found it’s not by filming good angles, but by moving through the space of the buildings with people who had a real connection to Lou, using the buildings as dramatic settings. And you have to be willing to wait for a building; you can’t just show up one day and say, “We’re going to do Kimbell today.” I went to the site and stayed for a while, then captured the buildings in different conditions. I used time-lapse photography to show how the buildings changed over time.

Which building do you admire most?

They are all equally interesting, and in different ways. In filming, each required a very specific situation; we had to search for solutions to convey the character of each one. This revealed to me how much depth of imagination went into their design. They really kept me on my toes as a filmmaker. I was also surprised by how the buildings seem both big and small at the same time. Lou Kahn’s sense of scale is astonishing and mysterious. I felt it was essential to capture this: How do you make something feel both monumental and intimate? I hope we succeeded.