Greenhouse/Nomadic Living/Earth Berm all in one home

A friend of mine was paying a lot in rent and decided to do something about it, so he bought a used RV trailer, then built a building around it, and started to make a nice place. At that point, I thought he went wayward in his plans, as the "belikeeveryoneelse disease" got to his wife, and they started to build a "real house". I looked at what he started to do, and then changed a few things to get a low cost home, but was comfortable to live in, with the least expenses in utilities. Here is what I came up with.

I liked my friend's idea of using a RV trailer, because it is cheap, and contains quite a bit of the things needed...bathroom, running water, a kitchen etc. For him, it was a 39 foot rv that cost $4500. I also liked the idea that he parked his RV on a concrete pad, and then built a building around it. But the building was 16 feet wide, so that there was a sort of patio area outside of the RV, but inside the building, essentially making his living and dining room.

In this guys case, he built a standard building and insulated it. For me, I think I would build a shed shaped building, but have it as a Greenhouse with double glazing. This would allow solar gain to heat the building much of the time. A back up woodstove would help heat the building when solar heat was not quite enough. This greenhouse glazing would also keep the RV dry, something they are known for as mold and moisture can really beseech them. In the summer I would cover the glazing with opaque covering so it would not be overly warm.

To help insulate this hybrid home, I would earth bank the back of it on the North and East side with earth. This would add thermal mass, but also protect it from the cold. Inside this earth berm I would build a root cellar for food storage, access to that root cellar being from inside the building.

I would also make this shed shaped building fairly tall, that way over the top of the RV there would be storage area. That would be 8 feet wide by 40 feet long, so it would hold quite a bit of stuff.

As far as I can tell in doing the math, this would be a very reasonably cost home. Not counting the well and septic and all that stuff, but just the home itself, it would look like it would have a total cost of around $8000-$10,000. Not really bad for a finished 1000 square foot home. Here in Maine where utility and heating costs are high, this should be very low. A guy built a greenhouse over his regular house, and needs almost no extra heat to keep warm all winter long.

I had another house to move my family into, but i actually thought about building this for my own family at one time, and would have, but we had a cheaper housing alternative. Still I share this so other might consider the design, and for general discussion.

Possible other benefit?  If you get sick of the trailer after 20 years, you could demo it and finish out the interior with stick built walls.  Or remove a shed wall and upgrade the RV?

That's pretty interesting because it raises a possibility to me.  We have an issue where I live with tiny houses.  Although built on wheels, and some even being recognised as road worthy, the government has decided that they are homes because they are being lived in and not driven around.  So, they need to have building consents.  And if they don't get building consents they need essentially to be demolished even though we have a housing crisis.  The people with houses of course just say that these guys building tiny houses need to follow the rules!   Unless you're the Govt in which case you can exempt yourself from the regulations https://www.tvnz.co.nz/one-news/new-zealand/government-accused-hypocrisy-after-ordering-its-own-batch-tiny-homes-wheels

And the problem, apart from high costs for a building consent, is that you need a solid foundation and not wheels.

Now if a building doesn't have running water, or ablution facilities, and they are under 10 m2 in floor area, then they don't need to be consented.  

Maybe what people need to build are earth bermed structures, or an international space station like house, and you pull up your RV and dock to it.  Your RV has the cooking, and ablution facilities and the docking station has sleeping quarters.  If you want to move on, you just undock and drive away.  You'd just need some standards on how to dock to each other.