Somebody left a comment asking some questions about the house in Ojinaga that I wrote about a few days ago. I can't figure out how to respond directly to comments in Blogger, so I will respond here.
The house does have a lime plaster, but I'm not sure if it's the same as the plaster on the Kern house. I think it has two vaulted rooms in front. Not sure if it has any flat roofs or not.
I have one picture of the interior, showing the squinch that supports the dome.
Simone Swan explained to us how the squinch works and how it is built. The purpose of the squinch is to enable the builders to put a circle on top of a square: it makes the square building into an octagon. When the walls reach a certain height, a form is used to build a little arch in each corner, over the form. Then when the arch is dry, the wall is built up to the top of the arch, creating a new octagonal wall on which the dome rests.