Review: Oehler, M: The Underground House Book
Mike Oehler is an autodidact, and a man — he admits it, nay, proclaims it — of strong and idiosyncratic opinions. He has a recipe for building small dwellings cheaply in Pacific Northwest USA — which is to say it's as wet as western Scotland, warmer in summer and considerably colder in winter. He designs houses that I could afford to build using materials which are — with the exception of the polyethylene membranes which are key to his system — considerably more ecologically sound than most modern building materials. He makes substantial use of roundwood poles — which I have in abundance for the cost of cutting and seasoning them.
All these are reasons I should take him seriously. And yet, I'm wary. He's built — or claims to have built — remarkably few dwellings (two, as far as I can see, although people using his method have built many more). He doesn't seem to use any moisture barriers in his floors — in fact, he extols the virtues of earth floors. I simply don't see that working in Scottish conditions (In fact in the 'Update' section at the end of the book, Oehler now has a membrane under the floor of his house — which is now carpeted).
The other thing is that I strongly suspect that if you showed one of his houses to any self respecting British Building Control Officer you'd get something between a hearty guffaw and a shriek of horror. Indeed, Oehler's own response to building standards is clearly expressed on page 100 of his book: 'will a home built with the PSP system pass the code? The answer is, sadly, no... you may move to an area which has no codes...'
To cast or not to cast
To cast concrete or not to cast concrete, that is the question. 'Tis undoubtedly nobler not to. Cast concrete requires a huge amount of energy, and so inevitably has a high carbon cost. On the other hand, provided it's done right, it will stand and be useful for hundreds of years, so that energy cost is ammortised — potentially — over a very long time. But here's the rub. I don't need a dwelling that will stand for a very long time. I need a dwelling which will be reliably warm and weathertight for thirty years. After that, it's someone else's problem, and someone else may not choose to live underground.
The wood/epoxy alternative is probably but not certainly good for thirty years. If it starts to fail in twenty years, when I'm in my mid seventies and probably pretty broke, that's going to be bad news. I don't think it would, but it might. Also, the cast concrete structure is remarkably cheaper, and remarkably easier to insulate, than the wooden one. Given how tight I am for money, that's a very significant consideration.
Casting on-site is definitely out. I can't get a readimix truck to site, and I can't quality-control the concrete I can mix for myself on site. Also, the shuttering cost of casting on site is high because it would be necessary to cast a whole dome in one go. I had ruled out my original idea of casting off-site because I had thought that I could not afford the heavy equipment to move stuff on site. But Boy Alex's Unimog can do exactly that. Casting off-site is once again an option.
Structure Review
OK, I'm getting very close to the point where I have to commit to a structure for my new home. I have to apply for planning consent, and I have to do it soon. If — improbably — I get consent quickly, then I can build this summer. And that would solve a lot of problems.
Of course, I can't actually afford, now, to build the full structure I want for the long term, so it has to be modular: I have to be able to build some 'now' and some 'later'. So let's again review the arguments and the options.
Conception
The Fool on the Hill
I've sold my house and am buying, in effect, a field. And a bit of wood and a share in a common, but basically a field. This is foolish. There is no planning permission on the field, and I'm unlikely to get any. Also, it's still possible that the deal to buy the field will fall through, but my house is sold. This is even more foolish. The field is five hundred feet above sea level, at the top of a very windy ridge. This is getting idiotic. Because I thought I would have more money than I've ended up with, I'm buying more land than I strictly need; and the consequence of that is that even if I get planning permission, I don't have much money left to build with. This is mad. Oh, and speaking of madness, I'm recovering from a bout of mental illness. At least, I think I'm recovering. So, this really is insane... Oh, and I don't have any income. At all. I could claim benefit — my doctor would certify I'm not fit to work (and he's more or less right) — but I've chosen not to. This is crazy.
But. But not that insane, I'd like to argue. Not wholly irrational. There are reasons. I'm not certain that they're good reasons, but...
I will have enough land to be self sufficient, which if I'd been more prudent I wouldn't have. The land, despite its altitude, is actually good; it's well drained, faces south west, and grew a barley crop last year. It's even soil-association certified as organic. I could live on what it can produce. I probably have enough wood to be sustainably self-sufficient in firewood.
On Yurts
The last two nights I have mostly been sleeping in a yurt. No, scratch that. The last two nights I have entirely been sleeping in a yurt — it is much too cold to leave a foot stuck out for the sake of a meme.
Outside, that is. Inside the yurt it is quite startlingly warm — certainly much warmer than I would be at home. A small centrally located woodstove heats the space exceedingly effectively. My second night in the yurt was, coincidentally but rather fortunately, the windiest night for a year — and one of the wettest. In the depths of this cold, wet, violently windy night in early February, the yurt was cool. But not colder than I should have been at home, not draughty, and (apart from a slight anxiety about a tree actually falling on it) not insecure.
This yurt is from Yurts Direct, and is, I believe. authentically imported from Mongolia. It's about 6 metres in diameter — frankly spacious and generously propeortioned; it is in itself a work of art. The curtain which lines the wall has a damask weave with a crysanthemum pattern, in fabric somewhere between ivory and gold. The poles of the roof — some eighty-one of them — together with the roof crown and the two posts which support it, are of a burnt orange colour apparently individually hand painted, and yet with a regular repeating pattern, as are the doors. The doors comprise two inner doors and a single outer door, all housed in a substantial and rigid wooden frame, with windows in the inner doors and on either side of the door opening.