Building a shrinking house

Firstly, because of shrinkage, you're going to have to build your house about 6% taller to arrive at the final correct height. Keep in mind that doorways, window opening and and location of joist beams all need to be adjusted to ensure that they end up where you want them after the 6% shrinkage. You'll also have to compensate for parts of the house which will not shrink, such as stud walls, sheetrock, cabinetry, stonework against the house, upright posts etc. There are ways of dealing with all of these but not the subject here. Enough for now to say that you have to think about this and design this into your construction.
 
Whenever logs are laid on top of each other, as in a wall, they will connect in only one of two ways - along the 'long groove', where the two lengths of the log join each other and the 'notch', where the log crosses another log (generally at right angles though this is not necessary). Both of these joints need to be tight when the building is built but they also need to remain tight even after 4-5 years of shrinkage has occurred.
 
To join two logs together lengthwise in a scribed joint ie: where the logs perfectly fit each other as if they grew together, the logs are temporarily stacked above each other, roughly 4" apart and the two logs are scribed at the same time with a single scriber. That is, a scriber with two pens ( or pencils) is run along the length of both logs, held perfectly level ( using the built in levels on the scribers). This is done on both sides of the logs. When the log is removed from the building, a scribe line remains on the removed log as well as along the top of the log still on the bulding.
 
The current best practice is that on the log remaining on the bulding, a line 1" in from the scribe line is marked out and a deep V groove is cut along these lines into the log by running the chainsaw on eiter side of the lines at a sharp angle. The cut should come within inches of the center of the log. Marks can be made on the chainsaw blade to indicate the proper depth. Obviously near the ends of the log as you approach the notch of the other log, the deep V has to exit and it forms a boat shape.  This long groove will ensure that the check in this log will be upwards towards the log above it. On the log above it (which is now upside down on the ground) we cut two shallow cuts at a fairly steep angle along both sides of the scribe line, then another two cuts at right angles to it, so that we end up with a W shape. The centre part of the W must clear the deep V groove so occassionally some fine tuning must be done to ensure that the logs do not 'hang up' - ie: that there is sufficient clearance when the logs are put back together.

The W shape plays an important role in conjunction with our long V groove. Remember that the long V groove has forced our log to check inside the V groove. When it does, the log tends to splay apart. Now when it does, rather than creating an opening just anywhere, it will actually press tighter against the scribe line of the log above it. Therefore, now the joint will tighten as the log shrinks and checks, rather than opening up in inappropriate places.