There were so many sets built for this movie that some of them wound up never being used. They do sometimes feature prominently in the background, like the hairdressers, but they play no part in the story.
The book sequel was optioned, but this movie's box-office failure caused the project to be shelved. Since then, there was no movement on the future, making it as a once-in-a-lifetime adaptation, much like Mortal Engines (2018) ten years later.
Mayor Cole trips after the lights start sparking and lands on a painting of himself, smudging it. Bill Murray's character did the same thing in S.O.S. fantômes II (1989).
During filming, the main city was built in a paint house. It was nearly as big as a small town, and the actors, actresses, and extras were given maps.
A former paint hall in the shipyard of Harland and Wolff in Belfast's Titanic Quarter was converted into the city of Ember.