A system for constructing log structures includes a corner connection structure, a through-bolt clamping apparatus, an opening support structure, a butt joint connection structure, a log profile, and an exterior casing structure. The corner connection structure has logs with overlap portions shaped so that the overlap portions of the logs of a first wall overlap and alternately interlace the overlap portions of the logs of a second wall. A generally vertical slot extends through the overlap portions of the logs, and at least one spline is provided in the slot. The through-bolt clamping apparatus has a through-bolt extending along the height of the wall, a lower clamp arm coupled to the through-bolt and the bottom of the intersecting walls, and an upper clamp arm coupled to the through bolt and the top of the intersecting walls.