Thermal Value and Materials

Last night I was talking with Ron Brummond about the thermal efficiency of a log home. He asked how it compared to a "regular" house and I couldn't remember any exact R-value numbers to give him but I told him it was very comparable to a conventionally framed home - only different. Alas, here's the data:
A material's R-value (factor) is it's ability to conduct heat (allow heat to pass through). So, yes, wood has a lower R-value than fiberglass insulation (around 1.8-2.0 per inch for wood, 3.3 per inch for fiberglass). Wood resists less heat than fiberglass. But, there's another issue when talking about thermal value (or efficiency).
A material's thermal mass potential must be considered. That is it's ability to trap and store heat. A material with a larger mass (such as logs) will have a larger heat storage value, therefore having a much slower rate of temperature change throughout the material. A log wall will have the ability to store heat to warm a house, not just create a barrier to the outdoors.
Materials
There are at least 9 layers in a conventionally framed wall. From the exterior siding to the interior drywall, each material is individually added to the building - fastened with a specific fastener, or applied with specific tool. Each comes with its own instructions and is manufactured and shipped from a different place on earth. Every different layer holds a value based on the distance it travelled, how much packaging it required and how much handling it took to reach its destination. I think that if a person can learn to frame, sheet, mud and paint a wall - they can learn to scribe-fit two logs together. Why so many layers?
Next we'll talk about building waste....