In Switzerland, they also have what they call Fleckenwand, which can also be classed as bohlenwand in some ways (and sometimes is called that)

Fleckenwand might be the evolutionary step between a post frame and a log building. What it is is large timber corner's and posts now and then, with thick timbers as big as these posts stacked in between them, and grooved into them. From this, people develop the complex corner joints and abandon the posts altogether, and end up with Blockbau.

The Buhl of Danish and Bohl of German are probably from the same root word.

Before saws were plentiful, planks would indeed have been made by splitting out a tree trunk...

Bole, from Old Norse Bolr- tree trunk...