> The first generation of Vancouver Special owners were largely families who occupied the entire property.
I guess it's hard to get exact numbers on this, but the things I've read suggest that a lot of Vancouver Specials had multiple households right from the start. e.g. Barbara Pettit's excellent thesis:
"By the 1970s, the Special had a distinctive style and was spreading throughout the east side as the "popular plan." Neighbourhoods changed beyond recognition, and residents began complaining about its size, its appearance and its use as a multi-family dwelling."
https://open.library.ubc.ca/soa/cIRcle/collections/ubctheses...