Here it is, folks. The single creepiest building in the world. Move aside, cabin from Cabin in the Woods. Go away, AHS: Hotel. Nothing is more chill-inducing than the Bates residence.

Norman's Head

Norman's brooding home, with his mother sitting in the window, is one of the more striking images, not only of Psycho, but of all horror movies ever. Period. Against the modern America of functional apartment buildings, cars, and highways, the Bates house is a gothic throwback—an ominous reminder of tales of a terrifying past.

In other words: boogy boogy.

Philosopher and Hitchcock fan Slavoj Zizek has argued that the house is a symbol of Norman's psychology. That leaning gothic mansion is Norman's skull, in which his dead mother sits and rocks and issues stern commands. (Source)

Zizek went further—because going further is kind of Zizek's deal—and argued that the three levels of the house correspond to the three Freudian aspects of the psyche.

The top floor, where Mama Bates hangs out for most of the movie, is the superego. Mrs. Bates (and the third floor) act as the conscience, issuing commands and judges:

MRS. BATES: I won't have you bringing some young girl in for supper! By candlelight, I suppose, in the cheap, erotic fashion of young men with cheap, erotic minds!

That's what the superego does; it tells you you're bad, your sexual thoughts are bad, and that you should be ashamed of yourself. (No one likes the superego.)

The ground floor of Chez Bates is the Ego, the everyday self—where Norman is Norman, the everyday dude.

And then, in the fruit cellar, is the Id— the home of instinctual, icky desires. Zizek goes on to explain that when Norman carries his Mama down from her room into the fruit cellar, that she stops being a force of the Superego (removed, set up with rules) and begins to be a force of the Id (part of Norman's instinctual self).

Maybe, in fact, this is why Norman gets caught after bringing his mom to the fruit cellar? Once she leaves her place of Superego-like authority, she can't hide what "she's" been doing quite so well.

Your Head

Did Hitchcock actually plan out these symbols?

Well, probably not precisely. But Psycho is certainly fascinated with the idea of multiple personalities. And Hitchcock even throws in a psychiatrist at the end to explain everything, through elaborate psychoanalytic explanations. Hitchcock practically throws open those house doors to analysts.

And if you (like Arbogast and Lila) discover something unexpected, all the better.

Especially if you discover a corpse and scream. Hitchcock likes it when you scream.