The smart commenters on Socketsite, a local San Francisco real estate blog, are having a two-day conversation that may document a key moment in U.S. housing history. I’ve put up a Storify about it here, including counterpoint from an anti-gentrification conversation that some of us had about it on Twitter.

All this started early yesterday afternoon with the news that a developer proposed to build a new “upscale” residential hotel. For some time now, San Francisco developers have been putting up small units for frugal single professionals. But until now it has been under the heading of “micro-apartments“.

The first few Socketsite commenters responded with confusion and distaste, thinking of hotels as places where poor people live. But they’re not dumb. As of last night, and continuing today, the conversation has turned toward seeing middle-class hotel life as a business opportunity.

Residential hotels, known as “SROs” for “single-room occupancy”, have been stigmatized in San Francisco for two or three generations as places where only the poorest people would live. That was never entirely true but the assumption may have helped protect the rent-controlled tenancies of some actual low-income people. Because of anti-SRO snobbery, they arguably faced less competition for their housing.

Some of this attitude persists. Socketsite commenter Kyle has written this morning:

“There is no such thing as an “upscale” SRO. What kind of “upscale” people live in a room without a kitchen? This will very quickly become a place of filth and crime. I would rather live next to a homeless shelter than a seven story SRO.”

Apparently he’s never heard of the Waldorf-Astoria.

On the Storify page I’ve included some links to historical context for what, from here, seems to be a genuine turning point in American commercial attitudes.

[Added later: As one of the SocketSite commenters noted, some middle-class residential hotels operate under the label “extended stay”.

Meanwhile, a string of “mini-suites” in Seattle has moved another notch upward — but no more — in the level of stability suggested by its promotion page: “Short-term leases (even month-to-month) are available.”]