Tactical retreat in the face of overwhelming force
Well, we're no longer in the Summer Palace. Of our twenty days there, it rained on nineteen and blew a gale on five. Last night, the BBC was forecasting gusts of 82 miles per hour — literally hurricane force.
By dawn it was obvious that I couldn't really depend on the roof surviving; even if it did, sheeting rain was falling and fine spray was blowing through the Summer Palace, making everything wet. The shipping forecast was more soberly predicting force ten, and the BBC's 6am domestic forecast had dropped it's prediction to only 70 mph. If I'd just been myself I'd probably have tried to hold out, but the idea of trying to catch the cats after the roof had gone didn't appeal, and I decided to abandon ship while I could. I started to make things as secure as I could.
Neadless to say I didn't have the cat's transport box down at the summer palace. Ivan, who'd slept cuddled in with me all night, was still under the downie, so I emptied the cooking box and unceremoniously bundled him into it. I wheelbarrowed him over the hill to the farm; at the top I could barely stand.
The Summer Palace
Tonight is our third night in the summer palace. The experience is throwing up problems I didn't expect, as well as ones I did. I have an urgent need to find somewhere for a midden for food waste — far enough away that it doesn't attract rats to the summer palace (although the cats would deal with them), near enough that it's practical to use.
Clothes don't dry in the wood — there isn't enough air movement and there isn't enough sunlight. So I'm going to have to put a clothesline out in the meadow somewhere. That also has implications for my living economy: if clothes do not dry, I must be very careful about getting wet. Fortunately, I haven't yet had a problem with rain blowing into the palace — despite two very wet windy nights; so I think I'm probably OK there.
Going straight
The singlespace roof has a slight twist, and I love it. The inner triangle is three and three quarter degrees off square from the middle hexagon, which again is three and three quarter degrees off square from the outer ring. It's that subtle twist that makes the roof so uneuropean, so quirky.
There's a reason, of course. The reason is that I couldn't get rafters long enough to span the ten metre diameter internal space that I wanted; and I didn't want to have to make a very complex joint at the top of each pillar. But I've been spending the last week working very hard on working out how to make my dwelling simpler to build, lower carbon and, ideally, cheaper; and one of the questions I've asked myself is how big a single space could I build with the rafters I can get.
The answer is that I can get 4800mm rafters at 200 x 50mm cheaply — just as cheap per metre run as 3600mm rafters. Given that the rafters cannot go right to the peak of the roof and that the gradient is shallow, two 4800mm rafters will actually span almost ten metres. But that's the full span of the roof. The walls come inside that span. If I'm going to use straw bale — which I'm now thinking of very seriously — each wall is 600mm thick, and allowing 150mm for eaves that takes 1500mm — or 15% — off the inner diameter, and consequently off the floor space; down from 78.5 square metres to 56.75 square metres.
Wool gathering
Singlespace, as described in the essays up until this one, is a building with a concrete floor and wall, and extruded polystyrene as insulation. Both of these materials involve a lot of embodied energy, and hence are far from carbon neutral. They're also not local — they don't occur naturally on site, but need to be transported in. I need to use these materials because I've embedded the house into the hillside, and it's a damp hillside.
But, as Pete pointed out, I don't need to earth-shelter the walls. I could have a walkway round the back of the house. Then it could be drained much more conventionally, and the wall wouldn't have to resist the pressure of either earth or water. So the wall could be much lighter. If there were problems with it, access to repair it would be easy.
More significantly, it could be timber — and timber does occur on site (although if I plan to build this year I won't have seasoned timber of my own and will have to use 'imported' timber). Even 'imported' timber has a far lower energy cost than concrete.
East wind
It's in the nature of this place, up on its high ridge, that it lives in the wind blowing in off the grey Atlantic. Our winds are westerly or southwesterly 70% of the time. Being on the western side of the ridge, my croft takes the full force of them. That's the main reason why I'm designing my croft house to be earth covered, sunk into a natural declivity in the ground. But I don't yet have a croft house; I don't yet have planning permission. So I've built a temporary shelter, my summer palace, which is essentially just a platform in the trees with a crude tent over it. And because the prevailing wind is in the southwest, I've built it in the northeast corner of my wood.
All the time I've been planning and building the summer palace, the wind has been in the west, and the wood has given it good shelter. Today, it was virtually finished. Today, I moved the last of the furniture into it. Tonight I would have moved in completely, but that I have to go to Edinburgh at the weekend, and I didn't want to leave the cats alone in a place they weren't familiar with...
Tonight, according to the met office weather station four miles away, it's blowing force nine. From the East.