Elmo's apartment is where Elmo lives with his Mommy and Daddy. It is seen primarily in the Talk, Listen, Connect resource videos and Learning is Everywhere. The building was first introduced in Season 30, sitting adjacent to Hooper's Store and the arbor.
In Season 46, Elmo and his family were relocated to 123 Sesame Street, with Elmo's bedroom replacing Gordon and Susan's apartment.
Elmo's apartment as of season 46