Living in mine. It's still a shock when I don't wake up in the 1971 singlewide we lived in while building. We did all the design work, so it's built for our preferences.
Earth sheltered on three sides, with a metal roof and 8-10” thick spray foam insulation (this is a compromise from the green roof we'd planned, for cost and structural reasons, but I'm glad we did it). Ten inch thick pored concrete walls, waterproofed, French drained, and insulated.
The open wall (not buried) is south-facing and mostly glass. The house is two rooms deep, long, with a courtyard (to eventually be a greenhouse atrium)in the middle to bring light into the back. Only the man cave, bathrooms/utility, and library lack windows.
The place is set up for passive solar heating, and it works very well except on days like today, which feature much snow (for the South) and no sun. Still, though, with our thermal mass and insulation, we don't have to add much heat, and we're completely sheltered from the north wind. In the summer, the sun angle and deciduous trees keep us from getting heat in through the windows, the thick insulation and light-colored roof keep the top from heating up, and we stay nice and cool until outside temps go above 90. We do have to dehumidify in the summer; we'll see if that continues when the concrete cures more fully, but it may very well since we're Deep South and outside humidity levels average 80% in the summer.
High ceilings (10’) and large rooms (most are 16x16).
Concrete floors, fully insulated under the slab so they actually don't get cold (this week has proven that).
Full dog room, with a dog door that the cats can operate and two fenced acres for everyone (no litter box at all!) We built in a drain in the floor so we can hose it down if needed, and we have water in there to allow it.
We sit in the middle of 25 acres of forest -- no view of neighbors at any time, though we can hear the nearest one's hounds and rooster. No sound of traffic unless said neighbor goes up his driveway. No human voices; even that neighbor is too far away for that. I have nothing on my windows, even the sliding glass door in the bedroom, and no intention of putting anything.
The view is wall of forest in summer and a mountain vista in winter once the leaves fall. There's nothing manmade in that mountain vista because most of it is national forest.
Big, sunny kitchen. No pantry yet, but only because the place is a work in progress; there's room for a big one and a chest freezer.
Supplementary heat and cooling is two window unit heat pumps (we have them through the wall up high, not blocking any windows). One, an older one we moved from the trailer, died on us a month ago, and we've supplemented on that end of the house with kerosene for a couple of hours on cold days while waiting on a new one to be delivered. The things cost $600, which means our entire HVAC system ran us $1200 plus the $100 for the kerosene heater which will go back to the barn when the new heat pump is installed later this week. Power usage is high for this board, but we're all electric and average $80-$90 a month, which includes heating water, overly generous computer usage (three on at all times, plus charging of two iPads), and cooking all meals.
We will have a porch running the full 72 feet of the front, but so far it's only 32 feet, in front of the kitchen and living room. We'll roof the porch; we calculated the sun angles to let in winter sun under it, but we're considering going with clear roofing anyway -- the trees are sufficient in summer. We're going to see what April is like before we decide for sure. For now, the porch is an unroofed deck.
We'll age in place here. Doors and hallways are wide enough for wheelchairs/walkers, and the one bathroom that is finished so far has a step-in shower with a seat. The other will be a Roman tub, but for the moment it sits in place, unattached to anything and taunting us ever so slightly.
As of this summer, we own house and land outright. Taxes on land and trailer run under $500 a year; once the house is added (there's a year lag time), that may go as high as $2000 a year, but I expect closer to $1500. Once we get a conservation easement on the land, which may take another year after that, it will drop considerably.