A mountainman I know is building a house in Montana out of 'found stuff'. Free stuff. I asked him how he did it. He said: "The basement long wall is on the south side.What do you build over that basement space? Stonework! In the south, I know it would be some open lattice for breeze, but where we live is the frozen north, so ours is stone which warms a little during the daytime and holds that heat. Yessir, Stone. Well STONE abounds at mountain bottoms. Usually for about a mile around any mountain you'll find great stones of all sizes.So I pick up a few truckloads a week.

Now, the house will be enclosed with a green house off to the southern side. I build the house with  straw bales. That's right, straw makes a great insulated wall. (I use bales between posts mind you and the result is seriously stuccoed.)

I  dumpster dive for hot water heaters. But aren't they mostly broken, I say? Well, not so the water runs out of them, funnily enough. I use them under glass inside, for solar heat storage. The heat storage will have sensors that will run dumpster dived up muffing fans (12 volt fans from PC power supplies) for keeping the green house up to temp. There will also be the option to circulate house air with the water tank storage using the same style muffin fans.

The south wall of the "house" part, the up stairs main living area, will get flat black sheet metal roofing attached, then glazing over that (dumpster dived sliding glass doors) such that I can circulate house air over the black sheet metal (the inside wall will be straw baled and stuccoed) and get heated up and brought back in to the house via 4" square wooden ductwork built in to the bales and the collectors. This will eleminate the idea of siding, produce energy and it is fireproof. And yes, the place may as well be the frozen north in the winter. One morning after Xmas, I woke to a sense of the living room being rather cold.

A look at the thermometer said something like 12F. Then I realized I could not hear any sound from the wood stove, no random crackling. Switch the thermomter to inside reading: 32.5F

Get up butt naked, start fire in stove, go back to bed for half hour, wake up toasty. A few nights in Feb it went to just under 3F outside at night. First time I have ever been in temps that cold. As long as there's wood, house is toasty!