A house is constantly shown to the left, across the street (the Donahue's house) from the Hecks' home. This is the set house used in Bewitched (1964). To the right of the Hecks' home is the house used for The Partridge Family (1970) .
The fountain that appears in a few episodes is the fountain from the opening credits of Friends.
The town of Orson, Indiana, is fictional, but based on the real-life Indiana town of Jasper.
The original pilot episode starred Ricki Lake as Frankie Heck. Most of the cast was replaced after that production, with Atticus Shaffer (Brick) being the only actor remaining.
When the show started, Axl is a high school freshman and he's played by a 19 year old. Sue, a seventh grader, is an 17 year old actress. Brick is supposed to be in second grade, but the actor playing him is 11 years old.