[4][5] Since 1942, it has been home to the California Alpha Chapter of the Sigma Phi Society, the oldest national fraternity in continuous existence.

It houses members of Sigma Phi Society, hosts communal dinners, organizes small concerts, and offers tours for other students and members of the public, welcoming thousands of visitors a year.

[6] The Thorsen House can be toured throughout the week on an informal basis; one can simply knock on the door to visit.

The fireplace in the living room is encased in mauve tile from the Grueby Faience Company.

The front door contains leaded art glass in the pattern of a gnarled grape vine, executed by Emil Lange, who also worked on the Gamble House.