Think about these massive Middle-Ages cathedrals done before we had Newton's Laws and modern notions of engineering. How did the architects do it? Well, they were hackers with a large budget. The architect usually had never built anything on this scale before and had no idea how their much-smaller-scale building experience would scale up. In particular, the fact that arches create sideways stresses which tend to bulge a large, open building outwards wasn't necessarily well-known by many of these architects.

So what did they do? They just tried it and saw what worked. They hacked it together. If it doesn't start buckling and collapsing in the first month, it could probably last for a couple hundred years, maybe more if the ground doesn't shift in unexpected ways. The walls started bowing out? Then we'll build structures to buttress them back in. There's a dangerous sagging happening between these two columns? Well, place a third column in there!

Of course, wood offers a lot of questions as a building material, since it's got a lot of energy in a bioactive form which lots of critters and cellular lifeforms might enjoy eating, and therefore needs to be treated in ways that might tend to prevent these critters from using it as a food source. Keeping it not-wet is an important first step which isn't discussed very well in the article.

But for what it's worth, this was the way you built houses before we had engineering. You just went for it and spent a bunch of the year working on it, and it better be successful because you've got to have a place to sleep this winter.

That's a fascinating thought. I'd like to read more about this "hacking" aspect -- can you point me to any references / citations?

http://babylon.acad.cai.cam.ac.uk/students/study/engineering...

And here's a short book review about a book which might describe a dome that was hacked together on a budget:

http://www.reedsblog.com/?p=85

I was reintroduced to this by a recent BBC series on architecture, though, and I can't figure out which one it was! It could have been Climbing Great Buildings, which had some moments where they would sneak underneath these great cathedrals and see what little bits had been "swept under the rug". But it might have also been Churches: How to Read Them. (I vaguely think it's the first because I have memories of some reference to Durham Cathedral partially collapsing, but memories of this form are notoriously unreliable.)

Conclusion: we should develop ways so that we learn less by osmosis. When you learn by osmosis, it's very hard to track down actual sources for the crap you've learned, and you basically have to get lucky.

They didn't do it a lot of the time. It just seems that way because only the few cathedrals that happened to strike on a physical supportable design are still around. Ie, survivorship bias.

IMO, it is highly improbably that adequate structural analysis was done on all those small twisted members because branches and stunted trunks contain so many knots and so much sapwood.

On the positive side, the approach is straight out of Christopher Alexander's A Pattern Language, and any victims of the inadequate structural design will be due to Darwinian forces.

http://www.patternlanguage.com/leveltwo/ca.htm

Also, if you're ever in CO, it's worth the visit. Really.

My experience with county inspectors is they don't build anything.

They show up to inspect the work after it's done, certify it's to standards and call it a day.

If you're real lucky you'll get an inspector who is buddies with certain contractors in the area. Woe to the poor SOB who doesn't use them - you'll have a heckuva time getting that work signed off.

Yeah boy: how would we get anything done without county inspectors.