If your interested in cheap housing. Yurts are worth a look. They are used by half the population of Mongolia, and can be very warm. They make a great cabin retreat, but they are not quite as nice a normal american home without the added expense and convenience of plumbing, electrical, etc...
However, in there base form, they cost around $5000. See the link below for pricing:
I've got to point out, you've got to have the right climate for these earth-sunk homes. Insulation works great when it's dealing with convected air (IE protecting your house from freezing cold outside, and with building paper from a harsh wind too).
Whilst the earth provides great protection against summer heat (thermal mass), it offers you nothing against the winter cold. Seriously, I question this house surviving a winter in liveable condition. By his drawing, there's likely minimal to no foundation structure, which means his retaining walls are relying solely on their mass to hold back soil. Note that frost heaving can exert a force of 14,000PSI and you better hope your wall is big enough.
Modern built homes in cold climates (where I live, Canada) rely on footings below the frost line (so your house doesn't split in two or more pieces), the basement floor and first floor joists to supply the lateral forces to resist the freezing soil. Simply put, rocks on soil and timber shallowly buried is a serious danger if a heavy freeze gets under any of them.
I didn't say yurts were cold, they normally have multiple layers of canvas (or similar material) that acts as very effective insulation. Air gaps are often better than foam. IIRC <3cm of air cannot convect, meaning from a well formed air gap you could be getting a far higher R value than an inch of extruded/spray foam insulation.
What I said was that ramped earth walls provide little value in a winter climate and are in fact extremely dangerous. >4' of dirt against a laterally unsupported foundation wall is actually illegal in my municipality. I see no lateral support in this guys structure. His walls would have to be incredibly thick (which they don't appear to be) to support the weight. The timbers need to go down a sufficient depth, which without the use of machinery, is unlikely to have happened and unlikely to have had the soil re-compacted properly.
What I'm saying is that the $5000 this guy spent on a 'house' is likely to collapse and kill whomevers inside the minute frost gets anywhere near his walls, let alone under the foundation or timbers.
A yurt on the other hand, due to its tent like structure and completely using flexible building materials would cope extremely well with differential frost heaving (which is what cleaves houses in two).
If the houses foundation doesn't extend below the frost line, you've got two choices. Heat it like you want it to spontaneously combust, because you want to keep the frost line well away from your structure. Or 2, ride it. I've seen many cottages here in Canada built on grade that have survived decades of winters because they aren't tied to the ground they simply move when shifted.
In terms of heat the single slow-combustion-wood-fire will be plenty (assuming a good wood supply) to heat this relatively modest space in winter (in Wales).
As for the frost, it might be an issue in a real heavy winter, but Wales is not Canada. Also, the dissapating heat from the building will help, and timber is inherently far better at handling structural stresses than concrete/steel/etc. That said, I hope for his sake the hill-side retaining-wall is built well (well-drained, structurally strong, etc.) to ensure this doesn't happen.
Not saying it won't cause an issue, but I think you overstate the case somewhat.
In Wales, no this isn't likely a problem. However, due to temperatures staying near-zero it can be worse on a structure if it's regularly cycling below freezing at night.
I wouldn't trust the retaining wall if it wasn't at least 20" of masonry when it's laterally unsupported. Flagstone walls here with lime mortar, laterally supported on floor and ceiling cope at around 14" thick, at which point they can support 6' 11" (by the municipal bylaw) of earth, his walls are laterally unsupported, and by law here can't support more than 3' 11" (if built with a strength equivalent to 8" of 15 Mpa poured concrete, locally about a 14" flagstone wall). Well drained soil will help, but when you're building a wall into the face of a hill, you're being stupid and putting your house below-grade.
I seriously expect this house to fail in a bad winter. I would trust this house in warmer climates, but definitely not in anything colder. I'd also like to know if this guy got approval by a structural engineer, because I certainly didn't read it when I glanced over.
That's pretty cool, and, naturally, it looks like it was founded by some hippyish individuals not far from my home town of Eugene. Where else but Oregon or Northern California would people do something like that? :-) They do look like a pretty good option for a cabin for some land in the mountains. I wonder how well they do being left alone for most of the year.
My girlfriend's sister lived in one for almost 2 years in Southern Oregon. Held up just fine, no leaks, and it was around ten years old when she moved into it. She mud plastered the walls and painted using some natural pigmented paint she made, kinda cool. Compost toilet was a little walk down a trail. Southern Oregon doesn't get a ton of rain, so it's not that bad having one outside the house.
Shipping containers are often used, which can be had for half this used. Usualy a much better idea IMO. Refrigeration units offer good insulation, often alongside partial burying of them. They can also look fairly like the western norm inside.
I have heard that most shipping containers, even refrigerated ones, have quite toxic linings that can be difficult and expensive to remove. I can't find a source for this at the moment, but it came up as a problem for shipping container living in a reddit thread a few months ago.
I love the idea of the shipping container home, especially when fixed up like this - though I lack the skills/patience to DIY like in that link you posted.
There was an amazing compund a guy in Texas built from shipping containers, shown on the show "Doomsday preppers" on TLC the other day.
Looks like you'd still need a fair bit of structural steel to support that citycenterlofts building. I would say the engineering skill needed is fairly non-trivial, although straightforward -> i.e. not a low-cost DIY type of structure.
I'd be interested in seeing the construction costs of that though, as compared to a similar design not based on shipping containers.
I forgot about zerocabin - I had seen that site before. Thanks for the reminder.
Yurts are cool structures and relatively heat-efficient. You can find them everywhere now. In the western world at least, they are built with modern engineered materials most of the time.
What is cool about the OP is that it's totally built in the rustic style - sticks, logs, etc. This is a bit distinct from deciding to build a "yurt." For more examples, google it, or check out something like Dry Kye (http://drykyerustic.com/). Disclaimer: this is my cousin in Maine. He harvests his own materials and is especially fond of salvaging patina-ed, old-growth wood from very old abandoned barns in the Maine countryside.
Lived in a similar sturcture for about a year as a kid growing up. House didn't have enough room for myself and my brother, so we built one in our back yard. They're warmer than you'd think, quick to set up, and they last a while. Great for guest rooms, but make sure you have an outhouse available, or at least running water.
However, in there base form, they cost around $5000. See the link below for pricing:
http://www.yurts.com/products/default.aspx
(I am not affiliated with anyone selling any yurts, I just happen to like them).