The Carter G. Woodson Houses in New York became famous for a tragic reason: a serial killer stalked the housing project’s residents and the culprit was discovered to be someone who lived among them. A single building became a hunting ground.
Being writers, this struck us as a great starting point for a story. There are plenty of horror stories with characters trapped in confined spaces with something or someone that wants to kill them. Taking the story in a less gruesome direction, consider ways in which you can limit a story to occurring in a limited area, perhaps even in the space of a single building.
What if the lead in your romance story only dated people who lived in their building? What if the entire course of action in your thriller occurred in a few floors of a high-rise? What if the occupants of a building were cut off from our reality and had to face some danger with only their immediate neighbors? (This editor knows only 2 of his neighbors on his floor, and he’s pretty sure they aren’t great in a fight…)