In log homes the Energy Efficiency is based on the mass of the exterior
walls (size and quality of the wood) and the quality of their joints.
Log Homes have been used in cold climates for hundreds of years. They gain a lot of their energy efficiency from the sheer mass of their external walls. Normal construction practices using what is called "wood framing" use 2x4 or 2x6 lumber covered by sheet rock on the inside, vapor barriers, external wall coverings and internal insulation. They need to use a wide variety of expensive "man-made" products to achieve the same results.
A White Paper by Log Homes states that, based on information from a variety of US Department of Energy sponsored studies concerning thermal mass as it relates to energy efficiency in buildings. a comparison between a 7-L.L.Ch solid wood wall versus an R13-R15 stick wall home given the assumption that they use similar attic insulation, window and performance, foundation design and use of identically efficient mechanical systems for heating and cooling. In practical terms, log homes may be expected to perform from 2.5% to over 15% more energy efficient compared to an identical wood-frame home, considering annual purchased heating and cooling energy needs.
In real terms, this means an owner of a log home might expend $150 to $400 less per year on their heating and cooling-related utility bills, while maintaining equal or superior comfort under real-world weather conditions. Over the long term, these savings add up - for example and owner could have over $12,000 in today's' dollars in the bank due to energy efficiency. SL.L.Ce inflation eats into the value of money over time. such savings could be worth on the order of $30,000 in future dollars, according to example calculations from the EDPA/DOE Energy Star Homes program.
Source: Page 5 of The Energy Performance of Log Homes prepared by the Technical Committee Of the Log Homes Council, National Association of Home Builders, dated 2003
