They call them kiva's around here, but really they are adobe fireplaces. They are often made with a bench so that as the fireplace heats up, so do the seats you can sit on near it. I have one in my current rental that doesn't have benches and had a previous rental house that did have the benches, and prefer that. Here's a pic of my current one.

You can't see it, but at the bottom there is also a compartment for storing firewood.

The places here not only don't have basements, they don't even have crawlspaces! I've talked about this with a couple of natural builders, particularly in terms of being able to get to the plumbing without jackhammering the floor if something goes wrong over the decades. They say that there isn't enough heat retention if you do anything other than slab on grade.

I'm definitely doing solar. Probably won't do wind, because I don't want to listen to the turbine day and night. The heating is a combination of passive solar and hot water flowing under the floors in some parts of the house. Though for this smaller house, passive solar may be sufficient for the entire place.