Like Tim, Counter-Hewing seems to me to mean adjusting the timbers around the joints, but I could be wrong. All our old barns around here (central Indiana) are built that way. It's possible that in the case of a house where aesthetics is more important than in a barn, you would carry out this reduction along the whole length of a timber, or at least along a certain length so that it is not a sudden thing.
This isn't something that I will be dealing with on these timbers, because all of my joinery will be scribed on this project. The only measurements that have to be anywhere close to right on the money would be depth measurements of Posts, Plates, sills, joists and rafters. Their widths can vary by as much as an inch if they want to, or even more (the 1 inch range is my personal preference)
For those of you who are interested, I have been doing some further research into the authentic German Hewing method, and this is what I have found: This is the primary method used across central Europe, wherever people fell under German cultural influence, so outside of German speaking countries that would include places like Hungary and Romania.
In this method you traditionally begin by notching with a man on either side of the notch, chopping out the sides of the notch, bringing it very very close to the line, a special axe called a bandhacke is often used, but as it turns out you can use just about any axe. A small forest axe, such as the Gransfors/Wetterlings/Husgvarna forest axe (they all are the same design if you look closely) will do quite nicely. An American style axe would also work, but you would have to choke up quite a bit on its long handle. This axe is then used to split off the juggles from the top.
I find it quite likely that the bandhacke design, long and narrow with a very slight curve to the bit, is really designed to cut joinery (apparently it is very common in Central Europe to cut all joinery with an axe, and make little use of saws in carpentry) and found additional use for notching timbers. I say this because the design of the axe seems ideal for cutting tenon shoulders and that likes. It should also be noted that German carpentry makes less use of the mortise and tenon than English carpentry.
After the juggles are cut away, you go along with a breitbeil which literally means broadaxe, and clean off the surface. The Goosewing design seems to be the usual style.
The biggest trick then is to keep the second man busy after you have notched out the first face.
I have so much wood to hew it's not even funny! Although I have found out that I can make use of a lot of smaller, 'junk' trees which will make life a whole lot easier!
