WholeTrees Architecture and Structures roots itself in sustainable building practices through repurposing unwanted, disease ridden or invasive trees. Now the company hopes to expand the use of small diameter round timber in urban building projects throughout the state.

Roald Gundersen pauses halfway up the wooded trail, scans the trees around him and lets his architectural mind wander. Uninspired by the tall, straight trees, he slowly skims the trail searching for the “weed trees” that survive in the crowded woodlot by twisting and turning toward the light. Their unique, expansive branching patterns are stronger than traditional timber frame joinery.

They are exactly what he is looking for.

Doug Hansmann and Denise Thornton follow closely behind. They are the excited future homeowners of a non-milled, branching timber frame home designed by Gundersen and his team at WholeTrees Architecture and Structures in Madison. Della Hansmann, WholeTrees’ designer and, incidentally, Thornton’s and Hansmann’s daughter, brings up the rear.

Doug Hansmann points to a sturdy but lopsided walnut tree at the edge of the woods whose branches are stretched horizontally in one direction, begging for sunlight. Gundersen examines the tree and nods approvingly.

“This walnut will be the corner post of your bedroom,” Della Hansmann says. “Those horizontal branches are long enough to span the room and reinforce the wall.” She snaps a photo, and the walnut’s undulating form becomes part of the blueprints.



Over the course of a few spring days, 140 oak, cherry, walnut, pine, spruce and elm trees are added to the design of the home. They are diverse in width, height and branching structure, but these trees have a common thread: their removal improves the forest by thinning overcrowded stands and giving the remaining trees more potential to thrive.

“I fell in love with the convoluted shape of that lopsided walnut for our bedroom,” Thornton remembers. “I watched it and other distinctive and beautiful trunks as they were prepped and then took their place as timber posts and beams. The trees that hold up our house feel like old friends.”

Small-diameter round timber trees, like the walnut incorporated in Thornton’s home, are too small to mill and are often overlooked by conventional builders; however, Gundersen, the principal architect and co-founder of WholeTrees Architecture and Structures, breathes new life into these unwanted, disease-ridden or invasive trees by repurposing them into one-of-a-kind support structures in residential and commercial buildings.

The unique branching structures of the whole trees create awe-inspiring buildings that reflect bends and arches naturally found in Wisconsin’s landscape. By allowing nature to inspire and penetrate his designs, Gundersen hopes to reconnect people with the outdoors. He estimates that we spend about 94 percent of our lives inside and believes that the architecture of the buildings we reside in can have large effects on our overall happiness and outlook on life.

“We can transform quality of life by bringing inspirations from nature into the home and workplaces,” he explains. “It is freeing and comforting to bring a bit of the outside in.”

After founding his company in 2007 with his wife, Amelia Baxter, Gundersen sought to pioneer the use of local round timber in contemporary building projects with the goal of aiding forest sustainability efforts in Wisconsin and increasing jobs for local craftsman and artisans. In the process, he’s changing the way people look at round timber in homes.

“We get a lot of people saying ‘Oh, I remember the cabin we used to go to in summers and everyone has a story of a place that they had gone to away from the city,” Gundersen explains. “So then there’s this sort of lodge aesthetic or cabin aesthetic that has been [associated with] round timber. We are working to rebrand that into the 21st century.”

WholeTrees looks at round timber as a modern material for building, and recent research has exposed the strength, durability and environmental benefits of using whole trees as opposed to milled lumber, steel or concrete.

The U.S. Department of Agriculture Forest Products Laboratory, located in Madison, conducted structural testing of small-diameter round timbers and found they are 50 percent stronger in bending than a piece of milled lumber of the same size. This is partially due to the tree’s rings, which have a natural continuous, spiraling fiber arrangement.

“If you can imagine bending in yoga, this way and that way, you can feel the outer fibers of your body in tension. That’s just like with a tree,” says Gundersen. “So the engineering of a tree over those millions of years has really created that structural quality, and that’s the most important thing to understand about the material.”

Milling violates this structure and removes the strongest outer layers of the tree that have been naturally designed to resist the brunt force of wind. For that reason, whole trees are stronger than milled wood.

Structural testing by the Forest Products Laboratory has also found that whole-tree round timbers are comparable to steel in their weight-to-strength ratio in compression, when a force is pushing against an object, and are twice that of steel in tension, when a force is pulling on an object.

R. Bruce Allison, adjunct professor of forest and wildlife ecology at UW-Madison and a private industry cooperative researcher, believes that with better understanding of the strength characteristics of round timber, builders can meet building codes and construct reliable, long-lasting buildings.

“WholeTrees Architecture and Structures is making a significant contribution to sustainable forestry and building construction by establishing the technical reliability standards of round timber,” Allison says. “Today’s construction market favors ecologically sound, sustainable products used in creative, visually pleasing forms.”

WholeTrees selects round timber trees from public and private forests that are usually part of a managed forest plan. Once they are evaluated for aesthetic and structural strength, they are harvested, peeled and air-dried to ensure longevity. WholeTrees then stains or paints them before they are incorporated in straight and branched columns, beams, rafters and other interior elements.

WholeTrees’ process of preparing the round timber is the lowest embodied energy—the sum of all the energy required to produce a good or service—of any structural material. It requires less than two percent of the energy needed to process and transport concrete and steel for building. “Life-cycle assessment studies consistently show that wood outperforms these fossil fuel-intensive materials, such as steel and concrete, on all measures, including embodied energy, air, water pollution and global warming,” according to WholeTrees’ fact sheet.

Additionally, by taking these “weed trees” out of the forests, larger, native trees on the plot are exposed to more sunlight and carbon dioxide, which benefits the overall health of the forests.

“There are very few things we as humans can consume and potentially benefit the planet,” Gundersen explains. “But this is a potential area where, if you thin and prune a forest, if you garden a forest…The forest would love to be paid attention to, and part of that is really cutting and killing trees. That’s a very important role, and humans can handle it.”

WholeTrees’ “green” building philosophy and positive impact on forest sustainability is a very influential draw for homeowners. Theresa Marquez, a client of WholeTrees whose passive solar home is currently under construction near La Farge, in the southwestern corner of Wisconsin, wanted a house with a small carbon footprint and natural aesthetic.

“I have been in the organic industry for 40 years, and it seemed that having a home that was environmentally inspiring was essential and part of my lifestyle,” Marquez says. “I wanted to have a home that fit into the environment that it was in—rural woods and pasture.”

Each tree that is incorporated adds new shape and new challenges to the building projects and designs.

“The houses are very interesting looking. They have an organic line that most houses don’t have because they follow the shape of the tree timbers that are used,” says Thornton, who collaborated with WholeTrees to design her personalized home. “It’s not the cheapest way to build a house. Getting the artisans to put them together was the cost, but we decided that we wanted to support people working in the community rather than ship in cheap timber from the West Coast, China or Lord knows where.”

This attention to local artisans and builders is something that drew Thornton and Hansmann to WholeTrees. Thornton explains that they wanted to help their local community because, to them, sustainability is not limited to land. To be truly sustainable, you have to think about keeping your community sustainable, she says.

“One of our goals was to build green and operate green with really good energy efficiency, but also help create community and help support local people, and I think everyone that worked on our house is still good friends,” Thornton says. “I feel like it built not only a house, but built community.”

WholeTrees uses local builders and trees, allowing their practices to provide twice the number of local jobs compared with building projects that use milled lumber, steel or concrete. These projects typically use imported building materials, which consequently takes jobs away from Wisconsin construction and manufacturing companies.

Through their harvesting and building process, WholeTrees works with foresters, arborists, carpenters, builders and volunteers in local communities to provide opportunities for these local artisans and craftsmen to build a little differently and think creatively.

“People in Wisconsin, they love to be in the woods engaging the forest, and this will create jobs in those occupations,” says Gundersen, who believes that this can be true for cities as well. “It can lend itself to really crafted, beautiful, professional pursuits that could be very valuable in terms of being paid well to perform the work.”

While most of the buildings WholeTrees has designed are custom projects in residential areas, it is branching out and working to show that its practices are a competitive urban and commercial building option. This necessitates a cheaper and more replicable model of building that is also reputable.

“Currently our business has gone from this very custom business into one that is looking at making the material accessible—as accessible as blue jeans and BIC Pens, and low-cost vehicles like VWs—and make it into something that is accessible, repeatable, standardized and can be sort of plug and play,” Gundersen explains.

However, entering a metropolitan market with misunderstandings of whole-tree architecture is a challenge, especially when attempting to overcome current attitudes and change how people view urban building structures.

Marquez is excited about the potential of WholeTrees’ sustainable building practices spreading to cities in the state and nation; however, she is concerned about public perceptions.

“It is unclear just what materials the future will need to build energy-efficient, cost-efficient homes for the future, but WholeTrees is most definitely pioneering this, and, at this point, public awareness is the most important first step,” she says.

Gundersen believes that awareness can be taught and misperceptions can be overcome by not straying too far from people’s comfort zones and engaging the community in the design and building process.

“So if you think about it, the future of our cities in very large part could be grown from trees,” Gundersen says. “Big, banal buildings could potentially become beautiful, carbon-sequestering, local-job-creating and potentially forest-facilitating sorts of endeavors, and that’s exciting to me.”

Currently, WholeTrees is doing just this in their design of a grocery store for Festival Foods in Madison. This exciting venture is a first taste of how round timber can be incorporated into larger city structures and landscapes.

“Not only are we excited to be partnering with another local Wisconsin-based company, but are thrilled to be providing a solution to repurpose ash trees that need to be removed from the city,” says Mark Skogen, Festival Foods’ chief executive officer, in a press release announcing their partnership.

Thornton is enthusiastic about the possibility of these sustainable practices becoming accessible to more people and wishes others would take advantage of timber that is otherwise discarded or seen as not commercially valuable.

“I wish it would become more common to use the kind of wood that we used because there is a lot of it out there…you can see it everywhere you look, growing in stands all over the place,” Thornton observes. “It is actually strong and beautiful, and I think it will stand the test of time.”

Visualizing WholeTrees Architecture

About The Author

Lauren is a senior majoring in journalism with an emphasis on strategic communications. She is a visual and performance artist with a creative mind who craves beauty and connection. Equipped with a passion for puns, Netflix, hockey and rescue animals, she hopes to move to the Windy City after graduation and pursue a career in advertising.