Nathaniel Khan - the illegitimate son of the late, celebrated American architect Louis Khan - goes on an epic globe-spanning journey to try to come to grips with his father's memory in this overlong, oddly unsatisfying documentary. During his search, he explores Louis' architecture, and interviews his father's peers, fellow architects and friends, along with other members of his extended 'family' - the children of Khan's philandering relationships. If fact-based movies are the new rock'n'roll, My Architect is one long whine of feedback.

When Nathaniel Khan was a boy, his father told him fascinating stories about tigers and elephants, from his time spent in India. At the end of each evening, the family would pile into a car and drive Louis back home - to his wife and daughter. He always promised he would eventually settle with Nathaniel's mum. But, when Nathaniel was 11, Louis dropped dead. What effect this must have had on him we can only imagine - because the grown-up, coolly dispassionate narrator doesn't tell us. Possibly, it's the only way he can deal with it; ironically, the focus becomes more about his self-indulgent search (placing himself at the heart of every interview) than its fascinating subject.

"TOO WRAPPED UP IN HIS OWN CATHARTHSIS"

If Nathaniel aims to reveal, as a caption reads, "The Truth About The Bastard" - Louis, that is - he's too wrapped up in his own catharthsis to ever face the painfully obvious (something that may seriously try your patience during nearly two hours of often pretty meandering screentime): Louis was simply too busy haring round the world trying to make his mark to devote much time to any one of his three families. My Architect works best when it's glossily showcasing Khan's nobler achievements, such as the gorgeous Capital Complex at Dhaka, Bangladesh. But ultimately, this one's probably more geared to the confines of BBC Four.