From The Movie Snob:

My Architect (A-). This is an Oscar-nominated documentary about acclaimed 20th century architect Louis I. Kahn, among whose accomplishments are the Kimball Art Museum in Fort Worth and the capitol building of Bangladesh. Although his professional life was tumultuous enough, his personal life was even more so -- he was married to one woman and had one daughter with her, but he also had two other children, each with a different mother. This documentary was made by Nathaniel Kahn, Louis's youngest child and only son, who was 11 when Kahn died in 1974 at the age of 73. This movie is a heartfelt attempt by a man to understand the father he barely knew, as well as a very interesting look at the work of an influential artist. It starts to feel a little long (it's about 2 hours), but I can't think of anything that could have been cut without hurting the movie. Definitely check it out.