I understand that there can be a lot of tremendous startup cost to building an underground structure. Perhaps
that is why the Semi Underground trend took over such the supporting walls didn't have to be so thick and
the roof could be above ground and built of inexpensive existing technologies with loads of insulation.
But what I saw at an Earthship home I visited in Ohio showed me how inexpensive this stuff could be if one
is resourceful.
The couple who built the Earthship built a large sized Rocket Stove out of a 55 gallon barrel with a 35 gallon
barrel inside it. They had their own chimney design but I think it would be simpler to use a recycled dome lid
off a Weber kettle Grill and work the chimney ducting from that.
The floor had a layout of PEX flexible tubing laid out and street bricks arranged over the top of it as a thermal
mass. The Rocket Stove had a coil of 1 inch soft copper tubing wound around the 35 gallon barrel with a pump connected to one side of the heated floor tubing and the heated side of the coil connected to the other side. Hot swimming pool antifreeze mixed with water 50/50 was circulated through the PEX tubing in the floor
to heat the bricks up about 15 degrees. Then the heat could flow upward into the room to bring it to nearly
70 degrees F.
In the sketch above the supporting wall beside the window could be painted flat black on the side by the
windows and become a thermal mass, known as a "Trombe Wall". So the passive solar effect would charge
during the day time when it is sunny. If it were cloudy rainy weather for a few days the Rocket Stove could
be fired up to heat the floor. This is a very efficient system that burns twigs and small scraps of wood making it unnecessary to have cords of wood chopped and split to use in a wood burning fireplace. The wood burning fire place may actually make the interior too hot too quick. We're only talking a 10 to 15 degree F temperature elevation. This same Rocket Stove could be built with two domestic coils where one would heat
water in a Hot Water tank for showers etc where the other would be used for heating the floor.
Since the Rocket Stove uses so little fuel there won't be too much of a smoke signature from the outdoor
chimney vent.
Below is a sketch of the concept.
Rocket Stove example:
http://prepared-housewives.com/how-to-build-a-rocket-stove-and-impress-the-boys/
This is one of the advantages of such a structure.
Yes there are some expenses to produce such a facility. But after that the heating is very inexpensive. As
for electric, if you drive the Van to town two or three times a week the 6 volt deep cycle batteries would be
charged up so that you will have an electrical supply when you return for that night and the next day or so.
In town you may visit the Gym and work out and shower, shave, and clean up. Possibly do some laundry.
Then some grocery shopping.
One's smart phone could provide the broadband internet and once can visit web sites on the net for
TV programming, Radio/Music, and message board communication.
There are all manners of used plastic Farm tanks that can be had for much less than first issue retail.
I've seen septic tanks built out of some uncommon items such as cemetery vaults. (companies that make
these often produce variations of them for hunting & fishing cabins etc. Then the leach field plastic tubing
needs to be run from it. This would be more than adequate for one or two people in a Tiny Home. These
are generally sold on a cash basis and brought to site and installed in a six foot deep slot. A rental Ditch Witch
will quickly cut out the runs for the leach field. This stuff is usually done by the owner builder in a stealth
manner. The water cistern can be a group of blue plastic rain barrels in the back of the room.
Basically, I'm talking about a functional shell similar to a solar heated garage. The Van contains the home
element. In cold weather the solar Trombe Wall and Rocket Stove heated floor would provide for heating
inexpensively. In warm summer the interior would naturally be around 56 degrees F. Just a little solar
heating would adjust the interior to one's own comfort zone.
Lastly, an "Air to Air" heat exchanger or room dehumidifier may be luxuries items that could run a few minutes each hour. It would assure a livable environment in the most extreme weather conditions.
If I were to do this I'd want to find some property where there is a bottom beside the road or high way
so that I could grow some agricultural product on it. I'd have a dirt road into the hills where the Solar Garage would be located out of sight from the road. Then I'd try to get an Agricultural tax exemption on the property. If possible list myself as an "absentee owner" living in another state if that's possible.