Not sure if this is still the case ~25 years later, but when I lived in Vancouver in the late 90s, a lot of those DIY-finished basements were set up as (probably off-the-books) rental units to help cover the homeowners' mortgages.
I lived in one of those for about a year in-between actual apartments, and always thought it was weird how it was just slightly below grade. Thank you for solving that mystery :).
The first generation of Vancouver Special owners were largely families who occupied the entire property. By the late 90s either their kids had moved out and they had space to spare or they sold their homes (at much higher prices!) to families who needed to help pay the mortgage.
BTW the "slightly below grade" situation is helped by Vancouver having lots of hills -- in many cases the front door is at grade even though the average ground level is 18" higher.
> 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."
The ones in Vancouver, yes. Not so much in the suburbs, and despite the name there were more Vancouver Specials built outside of Vancouver than inside.
That "grade" situation is especially fun in very hilly areas - I remember a relative's house in Seattle somewhere that had three "ground floor doors" on different levels because the hill was so steep.
Even relatively flat terrain can have "walk out basements" which make what is technically a basement feel more like a ground floor.
I lived in one of those for about a year in-between actual apartments, and always thought it was weird how it was just slightly below grade. Thank you for solving that mystery :).