I discovered something last night that blew my mind. I had always assumed the Afterparty season 1 characters grew up in Marin County because Belvedere (where Xavierās mansion is) is in Marin County. (I'd headcanoned that Hillmount was in Strawberry or Marin City, two towns in Marin County that were both close to Belvedere and demographically more similar to the Afterparty cast than a lot of the other towns in Marin County)
But someone on Reddit pointed out that the police officers who come to Walt's house during the 2006 flashback episode are from the Kensington PD .
Kensington is not in Marin County. Kensington is an unincorporated community in the East Bay in Contra Costa County. And this tracks, because in Yasper's episode, Chelsea referred to Ska-pe Diem as "the premier East Bay Area high school ska band." By definition, Marin County is not in the East Bay.
The East Bay is basically the right half of the map below; Marin County is the peninsula on the top left. The red dot is Kensington, and it's apparently a 35 minute drive from Kensington (where Hillmount is presumably located) to Xavier's house in Belvedere.
This is a long way to drive to an afterparty for your high school reunion (especially if you have a six-year old in the car and it's 10pm), but if the afterparty is at an eight-figure mansion owned by an A-list celebrity, it makes sense that people would make the trek.
From my (admittedly cursory) internet research, Contra Costa County is a lot more affordable than either SF or Marin County, though there is a lot of geographical variation. The median home price in Marin County is just under $1.5 million (and Belvedere comes in at a whopping $4.7m). San Francisco is similar ($1.3m) but again, there is a lot of variation by neighborhood. The median home price in Contra Costa County is just under $800,000; Oakland is about $700k, but Berkeley is $1.4m and Kensington is over $1.5m. ("Started from the upper middle" indeed.)
I do, because I am a fanatical weirdo about this show, but I also think it is a super interesting detail in its own right.
The show heavily implies Yasper attended UC Berkeley, which is a twelve-minute drive from Kensington. I think this puts into sharper perspective the degree to which Yasper remained stuck in high school. On a similar note, it means that Xavier bought a house in the next county over (instead of buying a mansion as close as possible to home).
We still don't know where any of the characters live except for Xavier. Zoe and Brett are probably still near Kensington, since Zoe works at Hillmount. But Yasper, Aniq, and Chelsea could live in Berkeley or Oakland. They could live in San Francisco proper. Theoretically they could also live in Marin, but I think that is less likely if they did not grow up there since it is pretty expensive. My guess is that Chelsea lives in Oakland or one of the more affordable areas of SF, and that either Yasper lives in SF and Aniq lives in the East Bay, or vice versa (i.e. there is some geographical distance, because they hadn't seen each other in the 2 years prior to the reunion).
We also don't know a ton about the size of Yasper's AV installation business or its geographical reach. If Yasper's company is based in San Francisco, it must be doing pretty well relative to its competitors for Xavier's assistant to have picked it. If it's based in the East Bay/Marin County, maybe there is less competition.
Thank you for coming to my TED Talk. I am delighted I can still make new discoveries about this show 2 years after watching it.