Energy efficient log cabin from

When you are considering the purchase of an existing log cabin or thinking about a new log home in the country, take a hard look at the energy saving features that are in the existing home and question the sales person carefully at the factory or showroom where you will buy your new dream home.

Because log cabins are made of, well, logs, they have a lower R-value [the capacity of an insulating material to resist heat flow. The higher the R-value, the better insulator it is] than a traditionally-built wall on a house with 2X4s or 2X6s spaced 16 inches on center with the cavity fill with insulation. A log cabin with 6-inch logs probably has an R-value in the range of 8. The conventional wall in a house, properly insulated, has an value of R-14.

It is true that the log structure acts as kind of a thermal battery in which the logs heat up during the day in the sun and then slowly lose heat at night, helping to keep the interior structure of the cabin warm. Anyone who has spent any time in a log cabin knows that this thermal battery idea works for a little time in the evening but by morning that cabin can be freezing cold, about the temperature of the air outside the cabin.

Additionally, logs have a lot of moisture when they are harvested, but give off the water as they dry or are kiln dried. They continue the drying process after they are used to erect the cabin, which causes cracks to appear between the logs that allow air infiltration. The best woods to avoid that shrinkage is cedar, spruce, pine, fir and larch…in that order. Once those cracks open, they need to be sealed and the cabin needs a good going over with a high grade caulk at least once a season.

A solution that many log cabin owners are happy with is to use the cabin only three seasons a year and shut the cabin down for the darkest days of winter. Another approach is to install a substantial wood burning stove and stoke it up for the cold nights. Another approach, if there is electricity at the cabin, is to purchase a couple of industrial grade space heaters, the kind of propane heaters that are used to keep construction sites warm.

Although it is problematic to insulate the inside of the logs, because those logs continually expand and contract throughout the year, you can take two actions to perhaps make the cabin somewhat warm and comfy for the cold months: you can insulate the floor of the log cabin, which tends to lose about 20 percent of the structure’s heat, and you can insulate the roof, which loses about 50 percent of the heat.

Another measure you can take is to use double-glazed windows on the cabin.

What Do Log Cabin Manufacturers Do?
What do the manufacturers of log homes do to boost the energy efficiency of this building technology that dates back in the U.S. to the 1600s? One company, Wisconsin Log Homes, which sells long homes in a state not known for its warm winters, has developed its own Thermal-Log technology. The Thermal-Log uses a 2X6 core wall that the company says boosts insulation values three to four times greater than the ordinary log used in a log home. The company goes on to claim that the R-value of a typical log, as mentioned above, is about 8, the typically constructed wall is about 14, but their values in the Thermal-Log wall can reach R-50+.

A company in the state of Maine, Katahdin Cedar Log Homes, takes insulation seriously by offering its customers several packages to keep their log cabins warm. With one package the company offers a sheet of continuous insulation on the inside of the logs, which is then covered with cedar paneling–the interior wall surface. This option boosts the R-value of the walls to R-14, which is what you normally get in conventional construction. It has another package as well that boost the R-value to R-23.