Richard Beckinsale died before shooting (having been absent from the sitcom's final 1978 run due to other work commitments); consequently his medical student Alan Moore was loosely reworked into art student John. Leonard Rossiter encouraged Christopher Strauli to play the part as Beckinsale had, to guarantee laughs. Strauli found this uncomfortable, not least as his RADA contemporary had only died relatively recently. He recalled the part as an extremely unhappy one - despite the affability of the director and the rest of the cast - but reasoned his strained relationship with Rossiter was due to the older actor being deeply unsettled by his replacing a deeply-missed friend.
The film is essentially an opening-up of creator Eric Chappell's original 1971 stage-play "The Banana Box".
When Joseph McGrath directed the movie, he had never seen the original television series, so had no idea that the script recycled material from it. He thought it was all original material and shot it in his own style.
Rising Damp (1980) won many awards, most of them to the complete surprise of its creator Eric Chappell. The film won Best Comedy Film, and Leonard Rossiter, Frances de la Tour and Denholm Elliott all won awards for their performances. Even Joseph McGrath won the award for Best Director.
The film is unusual as it was shot on location inside the same Notting Hill house used for the exterior shots, instead of using a film studio for the interiors.