Increasingly rare in the Bay Area in general. Increasingly unheard of in the City. I'd say that in my experience the only folks having kids these days in the City are Asians in the Sunset and Richmond, latinos and some whites in the Mission, blacks in the Bayview / Hunter's Point / Western Addition and a very thin scattering of various others elsewhere. Most of our friends there (including many who are considering having kids but refuse to even think about it until they get out of the City) are DINKs, typically with pets. At the time we left the Sunset a few years ago that was one of the few areas where you'd seeing normal families. When we first moved down the Peninsula all of the sudden it seemed like there were families all around us, it was a profound change; and mind you I am comparing with a very residential part of the Sunset with few multiunit structures (excepting in laws). Sadly, even where we have moved to, slowly but surely families are leaving and being replaced by other arrangements. As I see it, the remaining portions of the Bay Area that even come close to being as "family friendly" as other parts of the US (be they metros or rural) are parts of the South Bay, much of the East Bay and most of the North Bay. The City and the Peninsula are definitely not moving in a family friendly direction and it would take substantial changes in economics, demographics and local politics (including much loosening of Green wacko growth restrictions) to change the trend.