Are there other impenetrable vault designs that don't involve kiln (or other buildings) walls and hearthfires for doors? So far the proposals I've made to my own village have been shot down thusly:
kiln vault: "kiln walls are ugly"
drying rack walled vault: "one mistake placing then and it's ruined, and you can never fix it, and it'll forever mar the landscape"
firewall vault: "can be burned through while everyone's offline" (quite true, and it takes a massive amount of labor to build)
Other have said they'd simply store things in their house, and either put their hearth in front of the outside door (doesn't stop people from getting in, just makes them get stuck when they come back out, so they have to teleport home), or put their hearth in front of the inside door to get intruders stuck on entrance, which isn't possible because the game doesn't let you put it there (unless you can manage to do it with shift-placement?). Obviously even if this worked it would only allow one person in.
I was figuring the best one was the kiln vault, with walls of kilns on three sides, and a row of hearth fires for an entrance on the fourth side, designed so that if other people join, two new kilns can be added in the front, and the hearth fires moved forward to make room for the new hearth fires.