Building Energy Code Compliance for Log Homes
Because log homes don't have conventional wood-stud walls and insulation, they often don't satisfy most building code energy standards—usually those involving required insulation R-values.
However, several states—including Pennsylvania, Maine, and South Carolina—have exempted log-walled homes from normal energy compliance regulations. Others, such as Washington, have approved "prescriptive packages" for various sizes of logs, but these may or may not make sense in terms of energy efficiency.
The American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) 90.2 standard contains a thermal mass provision that may make it easier to get approval in those states that base their codes on this standard.
To find out the log building code standards for your state, contact your city or county building code officials. Your state energy office may be able to provide information on energy codes recommended or enforced in your state.