The Key House exterior and interior is completely built from scratch by Netflix.
The pilot was originally shot for streaming service, Hulu, who decided to pass on the pilot, and it was then picked up by rival streaming service, Netflix.
Kinsey's head mall is the same as Starcourt Mall from Stranger Things, another Netflix show.
The original comic book takes place in Lovecraft, Massachusetts, which is a tribute to H.P. Lovecraft, a 19/20th century author of gothic horror stories. It was changed to Matheson in honor of writer Richard Matheson, whose work provided much of the inspiration for the original comic.
Jackson Robert Scott (Bode) also acted in the 2017 remake of IT and its sequel; IT was created by Stephen King, whose son Joe Hill is the creator of the comics on which this show is based.