Mama and Papa Hanson (Irene Dunne and Philip Dorn) are Norwegian immigrants bringing up their family in 1910 San Francisco. Every week they sit down in their modest home with their four children and Mama carefully divides the meager family income between the household expenses. "Is good", she would then say ... "we do not have to go to the bank", greeted all around by smiles; once again they have scraped by.
The eldest daughter Katherine (Barbara Bel Geddes) had always dreamed of becoming a successful writer. In a flashforward she has just completed her first manuscript, a story about her own family. She reads aloud ... "For as long as I could remember, the house on the Larkin Street hill had been home"... then she describes each family member, concluding with ... "But first and foremost, I remember Mama".
Then ... there was an earlier peek, below, of the view through her attic window, above. It looks out through the fog to the Ferry building and waterfront but was it taken from Larkin Street? No way.
Then ... more of the same view is seen later as Mama hangs out the washing on her balcony.
Then ... and the part of the view obscured by the washing on the right hand side, above, is revealed from inside the house, below.
... a vintage photo ... So where was the window view taken from? The circa 1920s postcard photo below (pre Bay Bridge) reveals the answer ... this is the view to the east from Nob Hill's Fairmont Hotel at California and Mason. Even the shadows cast across California Street, right of center below, are identical. We conclude then that the house scenes were filmed on a studio set using this view as a background to imply the location.
... and Now, more than eighty years later from the Fairmont's Tower annex the same view is unrecognizable because of the vast transformation of the Financial District. The Bay Bridge has since 1936 reached over to Oakland via Yerba Buena Island and the Ferry Building is still there but hidden from view. One structure visible Then and Now is the Old Cathedral of Saint Mary (arrowed).
Old Saint Mary dates from 1854 and has functioned as a church on California at Grant since 1891 after its cathedral status was transferred to a site at Van Ness and O'Farrell (a glimpse of that was seen in this post from The Conversation).