UNL uses red cedar to build a "carbon sink" house

The building is unique, because the timber is almost entirely sourced from Cedar Point’s forest of eastern red cedar trees.

Sourcing the wood locally also has allowed the project to be carbon-negative.

“When we calculated it, we embodied (released into the atmosphere) six tons of carbon,” said grad student Doug Rief. “But we sequestered 7.85. So it was a net gain of sequestered carbon when we got done. If we had done it traditionally, where we’re buying wood from say, Canada, which is where a lot of cross-laminated timber comes from, it would have been an excess, it would have actually created about two tons of carbon.”

The small cabin, called “Mizer’s Ruin,” has a “four-square” design, with housing occupying two of the squares, joined on the diagonal.

Two more squares make up individual porches facing the north or south, depending on the inhabitant’s destination.

The eastern red cedar that makes the bulk of the building is laid in square beams, stacked one on top of the other to form the walls, tied together with joining screws.

Dubbed a “micro-dwelling,” it is only 190 square-feet in size. The external walls of the house were charred through a technique called “shou sugi ban” which involves blackening the wood and applying oil as a preservative technique.

Completed in partnership with UNL’s College of Architecture, Associate Director of Cedar Point Biological Station Jon Garbisch encourages students to earn school credit through building projects at Cedar Point.

Ranging from biological studies to architecture and even artist retreats, the station gives students a chance to conduct field studies and projects in their respective majors, Garbisch said.

Architectural students are able to work on projects with wood harvested from Cedar Point. Students will cut down trees, mill the lumber on site and transport it back to Lincoln for later processing if needed. If not, they will use the lumber directly milled on site for construction purposes.

“What the students and I were just doing today is just cutting the bark off, making these billet beams that we’ll then slice up into one-by material or two-by or three-by material,” Garbisch said. “And that wall in the bathroom they’re making here, they’ll grab a couple of those, slice them up into three-by tongue and groove going up.”

The house still needs some work. On Friday and Saturday, grad students were working on utility hook-ups, framing a bed, sealing the walls with caulk and constructing the bathroom. They still need to install mosquito screens and add little details, such as trim round the windows.

Rief said they will have the house done in about two weeks if things go according to plan.

According to a 2022 release by the University of Nebraska Lincoln, the tiny home was first conceived in 2018, with further development in 2019 and finalization in fall 2021.

The Nebraska Environmental trust awarded the project $28,412 in 2020. A release said the funding “resolves concerns about the environmental impact of eastern red cedar in Nebraska.”

The design has also been submitted to the Association of Collegiate Schools of Architecture Design-Build Award for consideration.

Rief said the goal was not only to make a house for grad students to work on, but also to see if they could create something carbon negative.

The main consumer of carbon was transportation and processing according to Rief.

“That’s one of the things we’d really like to get, more milling equipment up here, because it reduces our carbon footprint even more,” he said. “It costs us $50 a student just in gas to bring them up and take them back.”

One of the reason’s Mizer’s Ruin received its name was the use of a Mizer saw mill to process the lumber. Mizers are portable mills intended for homesteading and locally sourcing timber.

“We’ve thought through so many different problems that we would come up against and have ideas about how we would do it again,” said Jason Griffiths, project lead and professor of architecture.

“The whole thinking behind the building was to use eastern red cedar and at the same time mitigate the threat of forest fire, particularly in canyons,” Griffiths said. “The idea was just to see if we could find some way in which the purpose of the timber and the way in which we think about it as a resource can be turned to a more positive tone.”

Garbisch said the purpose of harvesting timber from such a close proximity has two roles: fire management and keeping captured carbon in its captured state, also known as carbon sequestration.

“If you had a 40 acre parcel that was full of older cedar trees, these dense cedar thickets, like we see in front of us really are not usable habitat for the wildlife,” Garbisch said. He points to the sides of the canyon containing the biological station. It’s full of trees.

“We’ve removed at least 50% to 70% of the tree mass. Right now, after almost two years, you can’t hardly tell,” he said.

Eastern red cedar is not popular as a wood, Griffiths said, however he and the students set out to prove the tree, normally regarded as an invasive species, can be useful.

“I don’t see any reason why we shouldn’t think about it as building material.”

Griffith said any advantages eastern red cedar has over the industry standard yellow pine is doubtful.

“Eastern red cedar should be seen as another timber source that is different from yellow pine. Harvesting is a specialized process because it is not grown under managed forestry,” he said.

The aim wasn’t to prove eastern red cedar’s advantage as a wood on the market, Griffiths said, but to show a house can be built while minimizing the carbon footprint required to build one. Locally sourcing materials means less in shipping and fuel consumption.

“If you reduce the amount of travel, you can sequester carbon and help reverse the build-up of greenhouse gasses. But this idea of local construction also benefits local carpentry and forestry economically,” Griffiths said.