Singlespace joinery detail
If the 'singlespace' design is to be built it has to be built quickly, and largely with my labour. Therefore there is not time (and not skill, either, really) for fine carpentry or elegant carving. Yet the structure is going to be exposed and needs to look good. What I'm considering in this essay is how simple carpentry can result in an elegant structure.
In my initial sketch of the structure I discovered that in order to avoid complex joins at the pillar heads, each pillar/ring beam assembly has to be rotated about the axis of the building by an odd multiple of the rafter spacing angle of the 'upstream' assembly. The rafter spacing of the inner ring is 15 degrees, and in both this drawing and its predecessor the second ring is offset by 15 degrees. The rafter spacing of the outer ring is 7.5 degrees; however, if you offset the outer ring by just 7.5 degrees it just looks odd and so in this drawing I've offset by 22.5 degrees.
Every pillar has exactly one rafter running through it, and the pillar is slotted to take the rafter. A single treenail positively locates the rafter to the pillar. Every pillar stands at the junction between two ring beam components. The ring beam components are joined with a mortice and tenon, and are then checked back into the pillar. Finally, they are lashed together round the back of the pillar, enabling a strong characterful joint. The ring beam components are notched slightly on upper and lower edges to positively locate the lashing. Each of the braces is checked into the pillar and fastened to it with two treenails. The brace is checked to accommodate the ring beam component it supports and fastened with two treenails; the joint might be a little more sophisticated than the one shown in this drawing, but I don't think it needs be.
Singlespace
I'm revisiting the design of my proposed home yet again. Yes, I know this gets boring. But it's probably the biggest decision I'll make in the next ten years — I need to get it right.
I do like the four dome design — the design I've called 'sousterrain' — I've been working on over the past six months. It's scupltural and elegant. I think it would have elegant internal spaces. Because it's modular, you can add on modules; you can build only part of what you intend in the first phase, and live in that while you build more. Which I would need to do, since I can't afford to build it all in one phase, either in money or (probably) in time.
It's also very challenging for the policy driven, risk averse, conventional planning authorities; but frankly anything I design or want to live in will be, so that's almost a non-issue.
The Plan
Julie asks, what's the plan?
The plan, above all else, is to continue to live in the hinterland of Auchencairn, without having the money it now takes to buy somewhere here. That applies to all of us. The first stage of the plan has been to group together and buy a farm. That's completed; we've done it. Ruth has been the animateur of this stage of the plan, and as her share of the deal, she's got the farmhouse. So she doesn't need to build anything.
For the rest of us, we do. We don't, at this stage, have planning permission with which to do it. We're a mixed group, but usefully mixed. Boy Alex is a tree surgeon and feller, and intends to establish a saw mill. He's (naturally) thinking about a timber framed house, with Alice, who is a multi-media artist mainly working with film. James is an electrical engineer with a special interest in wind generation; if I'm up to date with his plans he's planning something like an earthship for himself and Vicky, and their young family. Justine and Si run a business providing up-market accommodation — mostly in yurts which they make themselves — at music festivals; their plans are slightly longer term but they have been talking about a straw bale or cob house to live in; they will use their land as a campsite and perhaps run yoga courses. Finn is a blacksmith, and doesn't actually plan to live up at the farm; but he is planning to move his workshop. Godfrey is a shoemaker; his plan is for a craft workshop and gallery, and perhaps a cafe, in the existing byre building. He also plans to establish a market garden, although in the end it might be someone else who does that.
Home
My parents rented the top cottage on Nether Hazelfield in 1965, when I was ten, and from that time I've always seen Auchencairn as home. Although my parents bought a house in Kirkcudbright in 1969, I returned to Auchencairn in 1977 to set up a pottery in the old mill. That business lasted until 1981, when Mrs Thatcher had her first recession and eight of the thirteen potteries in Dumfries and Galloway ceased trading, including mine. In 1982 I went away to University, and after graduating, worked as an academic in Artificial Intelligence for three years before becoming chairman of a spin-out company, attempting to market the products of our research. That company traded successfully until the recession of 1991, when it was wound up, and I returned to Auchencairn.
I've been here ever since. This is my home.
If I'm to stay here now, however, I need a home I can afford; and house prices in the village itself have become very silly, as more and more houses have become second homes or retirement homes for people who have not had to earn their living in Galloway's labour market. Consequently the Standingstone proposal has seemed to me a risk worth taking — it seems to be my best chance of staying in the valley. I appreciate that it is a risk.
Clutching at straws
In my last essay I discussed the possibility of using wool as insulation. After all, as I said, we have wool. The problem with using wool as insulation in the walls is that it has no structural strength and is not weatherproof; it must be packed into structural, weatherproof boxes. The wool is virtually free, but the boxes come expensive.
Well, OK, we do have wool. But we also have straw (and a square baler to bale it). This year we're growing three acres of barley on my croft, and thirteen acres across the farm as a whole; and no-one else is going to be bidding for the straw, except as horse bedding. Straw bales provide both structure and insulation. Indeed, the first straw bale houses, on the north american prairie, also had turf roofs, so there's no doubt whatever that they can sustain the compressive load. The insulation values — tested, again, over a century of prairie winters — are very good.
In straw bale construction, you need, of course the bales. In order to tie them strongly together, you need a certain amount of steel rod — about two or three metres for each square metre of wall. And you need a rodent-proof render on both inside and out. On top and bottom you also need something rodent-proof; boards are possible, but so is render. All this is cheap — as cheap as or cheaper than concrete blocks.