Off-the-Grid Cordwood Construction Community Center

Enlarge Image Image Gallery  This cordwood building is powered by the sun. PHOTO: RICHARD FLATAU

Thirty years ago, my wife, Becky, and I built our mortgage-free cordwood home in northern Wisconsin. Since then, as directors of Cordwood Construction Resources, we have written books, conducted workshops, organized the 2005 Cordwood Conference and provided consultation for potential cordwood builders.

In winter 2007, the Friends of the Merrill School Forest (an organization in Madison, Wis., that supports the school district’s forest) along with the Evjue Foundation, the charitable arm of the Capital Times in Madison, Wis., decided to use cordwood construction to build an education center on the school’s 764-acre woodland site in Merrill, Wis. The committee of “Friends” asked us to be the consultants and cordwood construction instructors for the project. The center would be used as a classroom, nature center and winter shelter, and would serve as a model for sustainable building and energy efficiency.

The committee had explored various green building methods and ultimately chose cordwood. Cordwood construction utilizes a low-cost, renewable, local building material — chunks of firewood — as the infill in timber frame construction. Cordwood has historical roots in Wisconsin. Door County, Wis., has numerous fine examples of turn-of-the-century cordwood structures (called “stovewood” at the time).

The Friends drew up plans, which were code approved, for the Evjue Cordwood Education Center. Volunteers cut 25 cords of tamarack during that winter (one cord is a pile 4 feet by 8 feet by 4 feet). In the early spring, the crew peeled the bark from whole logs with draw knives and peeling spuds, and later that spring, they used a portable sawmill to cut the timbers, posts and paneling. For the cordwood infill material, we used a buzz saw attachment on a John Deere tractor to cut logs to 16-inch lengths. Then we covered the rows and rows of split tamarack that were left to air-dry.

Sustainable All the Way

The framework of massive white pine corner posts and tamarack middle posts went up in spring 2008. Local high school construction classes came out to learn the art of timber framing and cordwood masonry. The general contractor gave lessons in safety, construction techniques, and the proper methods of squaring and leveling. An energy-efficient truss roof was erected and topped with standing-seam metal roofing. This roof truss design allows for thicker insulation for greater energy efficiency.

The building was oriented south for optimal passive solar gain. After establishing the solar exposure, we harvested the surrounding trees for firewood. To take full advantage of the solar gain, we used Energy Star efficiency guidelines in every phase of building. Generous local merchants and community organizations helped out: The Merrill Rotary Club donated a beautiful Vermont Castings Encore woodstove to provide auxiliary heat. Eleven casement windows, two steel doors and the attractive, split-faced construction block came from local businesses.