@Lightwizard,
My family bought a house in brentwood in the late fifties - it was not new, but not all that old at the time. I'd guess late thirties..
Next door was a house by Neutra, lived in by an older couple, who showed us around it at some point.
Anyway, that one's gone, replaced by what looks like a set of condos. And our former and less interesting house lives on. I found this out last time I was in LA and drove down the street for old time's sake. (That'll teach me..)
Two of my houses were old craftsmen, built in the 'teens. The one in northern california had major wood panelling, built-in cupboards, fabulous molding, pocket doors, very well built. The one in Venice was more of a beach cottage, but still had great features.
Of course 'old' varies.. depending on the part of the world we live, etc.