Poe's "Fall of the House of Usher" and Stevenson's "Strange Case of Dr. Jekyll and Mr. Hyde" have far more differences than similarities, but let's look for resemblances.
Both deal with moral dilemmas- Jekyll is trying to separate the good from the evil in an individual. Roderick Usher's plight deals more with an implied moral decay over the centuries that eventual causes his symbolic and literal house to fall. The moral dilemma is the very foundation of "Jekyll/Hyde" but it is less obvious in Poe's story, but still present. Poe writes in describing Roderick Usher's physical appearance: "a finely moulded chin, speaking, in its want of prominence, of a want of moral energy."
Usher's very demeanor seems in want of a moral energy that he sorely lacks which has brought him to his lowly station in life.
Both Usher and Jekyll are men of great financial means but their moral dilemmas bring about their death at the end of each respective story.