Continuing on with your question and blog post,

I am actually faced with some very similar dilemmas in my own research. I am faced in my research with 2 sudden revolutionary changes in carpentry practices -both with no clear reason as to why they might have occurred. Add this to the extreme inconsistency for the most part in building across the region my research focuses on -the entire Bernese portion of the Swiss Plateau- it makes it very hard to pin anything down and to see what is really happening.

But we face some this same confusion in America. Scribe rule barns, for example, were still built on occasion well after square rule had become the norm.

In Bernese timber framing, we have the situation where suddenly and inexplicably the entire approach to framing changed -twice- but did so on a regional basis and not a cross-cantonal basis. The first change involved abandoning the use of tall 2-story posts in the walls and heavy timber connection in exchange for a platform-based framing system (story-by-story construction) using lighter, simpler joinery. The second change saw a total revolution in wall construction, adopting what I would characterize as an Urban system involving half-timber construction with long slanting braces. The reason for both of these changes is not clear at all.

What makes this hard is I can't pin down a year or even a good range for any of this, because changes were so variable by region, and some communities held on to ideas for centuries that others had left. It's not even clear whether the tall post, heavy joint construction is even indigenous to many of the communities at all, and if rather these used platform methods -derived from log building- from the earliest times.

I can see, for example, a tall-posted house that may have been built around 1780, for example, and feel as if this is a good date for the end of that tradition. Then, on the other hand, you find in a different community a platform framed structure dating from close to 1600, and it makes you wonder what is going on.

For me, this is a question of whether or not Bernese timber framing actually arose from a single archetypal form that evolved in different ways and at different rates from region to region or if, rather, there were a number of vastly different framing traditions that gradually converged over time into a more-or less unified tradition.

Whatever the case, the rise of Half-timbered construction was a game changer (and I really don't know why. There was no timber shortage driving this change) which in many cases blasted away all of the older regional traditions. Half timbering in the Canton of Bern is, in a sense, their equivalent to balloon framing in that it was a single framing method that arose and supplanted everything else, perhaps for no good reason.