The second episode of the first series was the show's original pilot; then the producers made some changes which is reflected in the rest of the run. Differences include the lighting and Mark Heap playing Jim as a more (quasi)masculine, less strange character.
The family was based on Robert Popper's own family.
Almost a year after the series ended Paul Ritter passed away on April 5th 2021 from a brain tumor. He was 54.
When Tamsin Greig was in discussions regarding the part of Jackie, producers told her they were looking at Paul Ritter to play Martin. Greig was a fan of Ritter's work and said she would definitely accept the role if they could get Ritter on board.
Shown on Channel 4 in the UK and BBC America in the United States. A television pilot was filmed for a US version of the show, but was not commissioned to make a series.