I can think of no simpler way of constructing a durable, sustainable, well insulated natural home than the simple cordwood (or stovewood) method. Here is the 1884 Wisconsin Kruza house, 18" walls, white cedar and lime. Built by hand by a single man. 
The foundation is local field stone, rafters of hewn or sawn lumber, shingle roof and brick chimney. The chimney can easily be made from bricks dug and burnt on the spot. Interior whitewashed, the left end reserved for the family chickens.
As everyone interested in alternative building knows, the near legendary Rob Roy, Director of the Earthwood Building School, is the man to see about cordwood. Build debt free (and fire proof).
If you are short on cordwood or live near a sawmill that often produce odd stumps of planks or whatnot you can use any kind of wood just as well. If you are short on lime you can use clay mortar. It is free and the most environmentally friendly building material you can imagine.
Some people don't like the look of cordwood building. Fine. Clad it in boards, or brick, or stone, or mud; dress it up in ashlar or paint it to look like stone or tudor. Do it right and the cladding will further protect the structural walls and add insulation to the building.
