<P> Rick Moranis was originally cast as the janitor but left due to creative differences and was replaced by John Kapelos . </P> <P> In 1999, Hughes said that his request to direct the film met with resistance and skepticism because he lacked filmmaking experience . Hughes ultimately convinced the film's investors that due to the modest $1 million budget and its single location shoot, he could greatly minimize their risk . Hughes originally thought that The Breakfast Club would be his directorial debut . Hughes opted for an insular, largely one room set and wrote it about high school students, who would be played by younger actors . </P> <P> Principal photography began on March 28, 1984, and ended in May . Filming took place at Maine North High School in Des Plaines, Illinois, shuttered in 1981 . The same setting was used for interior scenes of Hughes' 1986 film Ferris Bueller's Day Off, which featured exterior shots from nearby Glenbrook North High School . The library at Maine North High School, considered too small for the film, prompted the crew to build the set in the school's gymnasium . The actors rehearsed with each other for three weeks and then shot the film in sequence . On the Ferris Bueller's Day Off DVD commentary (featured on the 2004 DVD version), Hughes revealed that he shot the two films concurrently to save time and money, and some outtakes of both films feature elements of the film crews working on the other film . The first print was 150 minutes in length . </P> <P> During a cast reunion in honor of the film's 25th anniversary, Ally Sheedy revealed that a Director's Cut existed but Hughes' widow did not disclose any details concerning its whereabouts . </P>

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