Duncan is a highly experienced producer and lighting designer who has lit over 150 shows in Perth, including many premieres of new Australian work such as Jimmy Chi's Bran Nue Dae, Jack Davis' No Sugar, Heather Nimmo's The Hope and Dorothy Hewitt's The Man From Muckinupin. His lighting designs for Black Swan Theatre include No Sugar, Bran Nue Dae, Sistergirl, Tourmaline, The Year of Living Dangerously, The Merry-Go-Round In The Sea, Closer, Plainsong, Cosi and Away. In addition to his lighting design work, Duncan managed the Western Australian Theatre Company from 1984 to 1990. He then became Dean of the School of Dramatic Arts at the WA Academy of Performing Arts before being appointed General Manager of Black Swan in 1999. Duncan's ongoing association with The Bread Trap began during his time at WAAPA.