Nils was the eldest son of a Swedish mother and Polish-American father who met at the Cranbrook Academy of Art in Michigan. He grew up with his mother in rural Sweden, completed university in Stockholm, and moved to the United States to attend Pratt Institute in Brooklyn, New York. Nils met Muriel while skiing in Zermatt, Switzerland. They married in 1978 and thereafter Muriel joined Nils in Brooklyn. Nils worked for The Walker Group, an architectural firm, before starting his own design group. He also taught as an adjunct professor at the Parsons School of Design.

Nils became a registered architect in 1993 and moved with his family to Keene, New York in 1996. He opened a small office in Keene Valley and began, at age 54, a relationship with Adirondack architecture that would become the great, burning love that defined the rest of his life. Refusing to engage with computer-aided design, Nils worked and reworked in graphite pencil, color pencil, and Prismacolor markers across pages and pages of drafting paper. He felt joy in a cantilevered roof, the way that pencil can add life to a line, dry gin martinis, the smugness of being left-handed, the stillness of the pond by his house, and the search for the perfect walking stick. Unable to gather supplies before his final trip to the hospital, Nils drew a sketch of his bathroom in order to direct his daughter to select the correct cologne. He never missed an opportunity to draw.

Nils is survived by Muriel, his wife of 44 years; Eva and Ana, his daughters; Christer, his brother; Taya, his sister; Coco; over 200 buildings across the Adirondacks; and many unfinished projects.

The M. B. Clark, Inc., Funeral Home is in charge of arrangements. Visit mbclarkfuneralhome.com to share a memory or leave condolences.