Stephen's house is the house belonging to Stephen/Stainless Steve Steel and was used as an occasional base for the Justice Force. The house appeared in the episode Return of the Justice Force.
After Domeoids attack Stephen's comic book shop and kidnap Metal Head, Stainless Steve uses his Justice Force emergency signal to contact the other Justice Force members. Then he catches a ride back to his house with the Turtles and Casey Jones.
The house is large, with a long, covered front porch and expansive foyer. Inside there is a good-sized library containing shelves filled with books.