Are Log Homes Really Green?

Log homes like many forms of construction can be green if built in a way that makes them green.  Modern log homes unlike their older counterparts are tightly built, have very little air infiltration and can be outfitted with all the modern heat exchangers, furnaces and insulation.  They can also be made very durable and incredibly long lasting with good roof overhangs, foundations that keep the water off the log walls and modern low to no VOC containing stains.

Carbon issues with logs

So with tight building and modern technology we know that log homes can be green but the what about the logs themselves.  The log themselves are essentially carbon neutral and since you can transport a house worths of trees on just a few trucks the transportation impact can be relatively small depending on how far the trees are transported.  You also have the option to plant seedlings to compensate for the trees you removed and the transportation costs.  Like any wood built home the carbon that is locked up in the fibers of the wood will remain there for as long as the wood doesn’t rot, burn or otherwise degrade.  In the absence of water any serious rot is unlikely so a good roof and foundation will be key to long term sustainability of the house.  On that note the longer the house lasts the better green credits it will get so good maintenance and good design can go along way.     

Energy Efficiency

In terms of R-value log homes by themselves are not as energy efficient as a modern stick built home.  For example a 6 inch log wall has around a R-value of 8 depending on the wood species and a 3 ½ inch standard wall will have a R-value of 14.  But there are extenuating circumstances to consider when looking at the thermal efficiency of a log wall.  For instance if you take the logs mass into account the log walls can act like heat sinks similar to earthen or concrete walls.  They can slow solar heating and and then release that heat into the space of the house at night when it's cooler.  It’s challenging to get a hard number to back up the many claims that log houses are more comfortable with less insulation but it would seem to be true.  

The general consensus is that when a log home is built properly, from sustainably harvested local trees and care to is taken to maintain and protect it from moisture a log home can be a very green way to build a home.    



Sources:

By Staselnik (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

http://energy.gov/energysaver/energy-efficiency-log-homes