You gotta check this house out, then go to the website and read ALL about it.
Here are some Key Points...
Dug into hillside for low visual impact and shelter
Stone and mud from diggings used for retaining walls, foundations etc.
Frame of oak thinnings (spare wood) from surrounding woodland
Reciprocal roof rafters are structurally and aesthetically fantastic and very easy to do
Straw bales in floor, walls and roof for super-insulation and easy building
Plastic sheet and mud/turf roof for low impact and ease
Lime plaster on walls is breathable and low energy to manufacture (compared to cement)
Reclaimed (scrap) wood for floors and fittings
Anything you could possibly want is in a rubbish pile somewhere (windows, burner, plumbing, wiring...)
Wood burner for heating - renewable and locally plentiful
Flue goes through big stone/plaster lump to retain and slowly release heat
Fridge is cooled by air coming underground through foundations
Skylight in roof lets in natural feeling light
Solar panels for lighting, music and computing
Water by gravity from nearby spring
Roof water collects in pond for garden etc.