The title is a play on the expression, "Building castles in the air," i.e. dreaming of achieving the impossible.
This film offered a rare substantial speaking part to "Queen of the Dress Extras" Bess Flowers, who plays Mrs. Smirch.
When Moe realizes he's drinking paint instead of coffee, he spits it out and it sprays on Larry's face. Larry looks right at the camera and shakes his head.
Production number 420.