Green Log Homes Bentonville AR
Log Homes Going Green
One of the oldest and simplest types of residential construction, log homes have always been green, since they're produced from what is fundamentally a renewable resource - timber. But in recent years, manufacturers of log homes have taken additional steps to address such issues as sustainability, efficiency, the health of occupants and the environmental impact of log home construction.
Builders of log homes have, in general, been conscientious about the timber they use for their homes. Many use dead standing timbers, for example, or wind-downed timber rather than new-growth logs. In addition, the use of reclaimed wood is becoming increasingly popular among log home builders, not only because of the beauty and stability of reclaimed wood, but also out of concern for preserving natural resources.
Reclaimed wood includes all types of wood species that have been rescued from other sources, such as wood from old barns, warehouses and condemned buildings, as well as wood salvaged from old wine casks, cider vats, bridges or even ships. Although it is generally more expensive, reclaimed wood has a special charm and timelessness that can rarely be obtained with new wood.
Sing Log Homes, based in McCleary, Wash., is using reclaimed old-growth timber for the components of some of its log homes. Recently, the company salvaged wood from the Posey Mill, one of the oldest woodworking factories in the Northwest. The Posey Mill had in part an aviation history, as the Spirit of St. Louis, the plane flown by Charles Lindbergh on his solo trans-Atlantic flight, once rolled out of the factory's doors. After standing for more than 100 years, the factory is now being taken apart piece by piece, and is yielding posts and beams more than 30 feet in length, which the company is using for some log homes.
Cabin Creek Log Homes, a Fairview, Tenn., company that restores antique log structures and builds new log homes, also uses reclaimed lumber and logs taken from vintage structures. Much of the reclaimed wood the company uses was harvested decades ago from old-growth forests, so the wood has unique qualities of size, density and color. In addition, the company uses logs manufactured from standing dead Engelmann Spruce trees harvested in Colorado. The logs were selected for use because of their low moisture content of around 10 percent.
Standing dead trees are those that have been killed by beetle infestation or forest fires but remain standing. American Timber Craft, a Utah-based manufacturer of fully assembled modular log homes and cabins, harvests dead lodgepole pine trees destroyed by beetle infestation. The logs are tested for dryness before harvest and are machined to engineered tolerances before use.
The moisture content of the timbers is less than 14 percent, notes company president Jack Nipko, whereas kiln-dried lumber often has a moisture content of about 19 percent or more. (Low-moisture logs shrink and split less than logs with higher moisture content.) Nipko says these trees are selectively harvested so only the best ones are removed. The logs are dimensionally stable, and after being installed in a home there is very little shrinkage, settling or movement.
Removing standing dead timber benefits the environment by using wood that would otherwise be a fuel source for fires. In addition, new trees are planted after dead ones are harvested, often under programs such as the Sustainable Forest Initiative, which was developed by the American Forest & Paper Association (see sidebar).
Other Green Benefits
Today's log cabins are green in a number of other ways. Often, the logs used for a home are harvested locally, reducing the amount of energy required to transport the logs to the site. Less energy and labor is required to process the logs, as opposed to finished lumber. Also, a log home requires fewer building materials such as dry wall, house wraps, insulation and siding, all of which are used in traditional construction.
Many of today's log homes are being built with logs that are pre-cut in a factory or sections that are pre-assembled before they reach the construction site. With this type of construction, there is less material waste, and the waste that is generated is usually recycled into other useful products. What's more, fewer construction hours are required to produce log structures manufactured in a controlled environment. In some cases, computer generated machinery is used by log companies, resulting in straighter logs that fit more tightly together.
Once completed, a log home's thermal mass can result in energy savings for the homeowners. Thermal mass is the ability of high mass materials (such as logs and concrete) to absorb and retain or store heat energy during warmer periods and to release it at a later time when the interior air cools. This absorption can improve energy efficiency by modifying energy demands.
Adding to the thermal performance of log homes is the industry-wide use of double-glazed insulated glass in windows, especially in colder (heating) climates. Low-e glass is a common upgrade by log home builders.
For the last 10 years, log companies have, in general, been conscientious about taking advantage of solar gain in their houses. Most of them try, when possible, to position their houses toward the southeast and to include additional windows on the southern side of the house.
To ensure a log home's building envelope is tight, builders use sealants such as chinking (a mortar-like material), caulking and foam gaskets between the logs to prevent water and air infiltration. The type of sealant used is dependent on the shape of the log and the manner in which the logs fit together. Chinking, for instance, is used to cover the seam between logs on the interior and exterior surfaces. Caulk is frequently used to provide additional protection on the exterior of seams created where logs joint together. Foam gaskets are common with milled profiles that join together horizontally.
There are other benefits of a log home that make it a popular alternative to traditional stick building. For instance, sound doesn't travel well through logs, so the homes are quiet, even when located close to busy roads. In addition, many homeowners enjoy the natural aspect of living in a log home, especially when the home makes good use of porches and decks to bring the homeowners more in touch with the outside.
The LEED Log Home
It's clear that log homes offer a lot of green benefits to homeowners. But one log home manufacturer, Alta Log Homes of Halcottsville, N.Y., has gone a step further by voluntarily participating in the LEED for Homes (LEED-H) pilot program, which was developed by the United States Green Building Council. Currently, Alta is the only log home builder participating in the program. (LEED, which stands for Leadership in Energy and Environmental Design, is a national rating system that ranks the design, construction and performance of green buildings, including homes.)
Alta is building a prototype log home that will incorporate a number of green and energy-efficient components. For starters, the home is carefully oriented on its site, so solar panels on the roof can perform at maximum efficiency. Trapezoid windows installed in the gables will enable the home to take advantage of passive solar energy. Throughout the home, the builder used Andersen's latest Low-E4 windows, which have a coating that reduces water spots, protects against damaging UV rays and makes them easier to clean.
The home will also feature efficient heating and cooling equipment, as well as a whole house air exchanger, which will bring fresh conditioned air into the tightly constructed home. In addition, Energy Star-rated appliances will be installed, and 80 percent of the home's lighting fixtures will use fluorescent bulbs, which will further reduce energy usage.
Throughout the house, the builder will install bamboo flooring from Teragren, located in Bainbridge Island, Wash. To treat the log walls, the builder will use eco-friendly, non-toxic wood coatings, stains, chinking and sealants from Sansin Corp., based in Ontario, Canada.
David Mann, vice president of Alta Log Homes, says he hopes to attain a Silver Level of certification for the prototype home, which is the second of the four levels in the LEED-H program. If the green log home generates enough interest among homeowners, he notes, many of its components will be incorporated into future log homes that Alta builds.
The Alta prototype log home, and others like it, will demonstrate to homeowners, builders and architects the benefits and savings that result from using energy-efficient construction methods and products. And it will no doubt add to the appeal of log homes, which will be seen as not only natural, warm and comfortable, but healthy, efficient and eco-friendly as well.
Sheri Koones wrote about alternative building systems in the January/February 2007 issue. She is the author of Prefabulous, a just-published book about prefabricated construction, as well as House About It and Modular Mansions. She's based in Greenwich, Conn.