Plant The Trees
In this podcast, we'll talk about all things agroforestry and what you need to know to plant, grow, and monetize your trees.
Plant The Trees
Building with Whole Trees and Structural Round Timber — with Amelia Baxter
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Amelia Baxter is the CEO and co-founder of WholeTrees. WholeTrees Architecture and Structures uses structural round timber (literal whole trees) to create durable, functional, aesthetically-breathtaking buildings and features of the built environment. The company was founded in 2007 to develop and sell products and technologies that would scale the use of underutilized or waste-trees in commercial construction. This increases forest revenues, and offers green construction markets a new material for the 21st century.
Whole trees uses species from the classic conifers to rot-resistant white oak and black locust.
We talked about how round timber can be dramatically stronger than milled lumber, designing buildings that feel like forests and how wood naturally calms the nervous system, how black locust behaves more like stone than it does wood, profit plus ecological balance as the definition of prosperity, and how structural round timber can re-shape rural forest economies.
Please welcome Amelia Baxter.
Round timber, it is 50% stronger in general than a milled piece of lumber with the same cross-sectional properties. Use low embodied energy and high carbon sequestration as a goal of your project, and it will automatically drive you towards wood. Wood, when properly protected and properly maintained, has an indefinite lifespan. Whole nervous system relaxes when it's around natural materials.
SPEAKER_00Today we're joined by Amelia Baxter, CEO and co-founder of Whole Trees. Whole Trees Architecture and Structures uses structural round timber, literal whole trees, to create durable, functional, aesthetically breathtaking buildings and features of the built environment. The company was founded in 2007 to develop and sell technologies that would scale the use of underutilized or waste trees in commercial construction. This increases forest revenues and offers green construction markets, a new material for the 21st century. Whole trees uses species from the classic conifers to rot-resistant white oak and black locust. We talked about how round timber can be dramatically stronger than milled lumber, designing buildings that feel like forests, and how wood naturally calms the nervous system. How black locust behaves more like stone than it does wood. Profit plus ecological balance as the definition of prosperity and how structural round timber can reshape rural forest economies. Without further ado, please welcome Amelia Baxter. Well, Amelia, welcome to the Plant the Trees podcast. You're the CEO of Whole Trees, which is a pretty unique business. How do you generally introduce whole trees for a mixed audience?
SPEAKER_01Well, it's good to be here, Harry. Uh here's what I say we engineer and fabricate solid round timber components for commercial construction. I would distill our product categories into columns, beans, trusses, and complex assemblies of columns, beans, and trusses, all made of unmilled timber. So solid round timber. Our company sells to markets ranging from schools to retail to zoo exhibits and to playground elements. If there's a little more time, I share that in the 1990s, my co-founder imagined unmilled round timber in new markets, way back when green construction, that phrase, was uh new to the lingo. Um we shaped whole trees with a combination of research and development, dramatic precedent projects uh that we used to capture attention, and then marketing savvy to reach new markets. Um, the rising awareness of mass timber in North America has been a real tailwind for our company as well.
SPEAKER_00And these logs, these whole beams and trusses, I'd imagine some amount of processing goes into them. They're debarked, maybe peeled. Could you tell us a little bit about taking a tree to a product that you all would use?
SPEAKER_01Sure. The most incredible aspect of a tree is how most of its processing occurs as it's growing. It is optimizing its structural engineering as it resists lateral wind loads and holds up its own axial weight. So our goal is to use industry-acceptable grading mechanisms to select trees for their strength properties. That's the biggest aspect, is the knowledge base to select different species for strength properties. Then we do we we purchase timber from managed forests and we bring them to facilities where either we work or we work with teens and outsource the fabrication that includes peeling and the fabrication of connection points to each other. And then the final sanding, buffing, sealant quality control before shipping. We'll ship products that look like logs, straight columns, beams, and we ship products that look like magnificent tree sculptures, which can be structural columns that are also branching.
SPEAKER_00And the size of these logs, I would guess it it ranges a good amount from say smaller, say a substitute for a four by four to substitutes for a metal I beam. Is that right?
SPEAKER_01Right. We use diameters ranging from 8 to 24 inches depending on structural application and the species. We will utilize trees selected for harvest by forest management plans. That's a like a baseline bar for us. And we do prioritize regenerative forestry. We originally envisioned that whole trees uh would be an innovator of new small diameter round timber products. But we've learned that the industry's still a few expensive steps away from implementing the grading procedures required to assign round timber. It's what I would call its rightful strength values. So we purchase timbers that can be quite large, and yet the removal of large timbers into higher value forest economies, forest products economies is still a bonus and a plus for generative forest management strategy.
SPEAKER_00That makes so much sense. And you mentioned the, I think it was rightful strength of roundwood. And it's my understanding that call it the basal area of a trunk of a log of a beam, if it's call it the area of a circle versus the area of a square, even if it's the same thing, if it's the whole intact tree, if you're comparing, say, milled six by six beam that would be 36 inches, call it basal area versus a round beam that is 36 inches squared in, call it area, that the round beam will be a lot stronger, even if it's smaller in diameter. Is that how that works?
SPEAKER_01The way we put it is that round timber, it is 50% stronger in general than a milled piece of lumber with the same cross-sectional properties. Another point of data, another way to look at it, is that any square piece of lumber milled from a round timber, once you cut the edges off of the tree and disconnect the outer fibers, it will be 33% as strong, a great deal weaker than the original round timber. And this is because the outer fibers of the tree are all working together in Congress to create enormous tensile strength for that tree as it grows. When you disrupt those fibers, uh cut off the edges, it's like you're cutting off the edges of a rope, which is also a group of fibers working together to create great strength. And uh, if you cut the edges off a rope, you know that it is not nearly as strong and you wouldn't want to use it. It's a really smart material, round timber. I'm very passionate about it.
SPEAKER_00Uh for those that are listening along, my office behind me is actually made of round wood. And uh the folks that built it said that they could probably park a bulldozer on top of it, and that weight was not an issue. So that sounds about right. Um, I'm also so we have a lot of artists and builders out in the Finger Lakes of New York that will do these specialty projects. And I think I also heard that a bunch of timber framers went to go rebuild Notre Dame. So you have these gorgeous structures. And I'm also thinking about, say, code and regulatory requirements. You and I know that these round pole structures, structural round timber, is stronger than necessarily uh what's required. Uh what's the status quo of fitting all of this into just I'll say conventional building, or you can correct me on vocabulary there. But what where are we at and kind of what are the what are the next steps in making all of all of these things more accessible?
SPEAKER_01Well, brown timber has a long history of code pathways and acceptance. And that's because of investments made by industries like telephone pole industry and the marine piles industry, piles being a word for timbers jammed into watery marsh or or coastal lines. And thanks to those investments, we have a whole body of work that tells engineers and code officials how to apply structural value to round timber of any species with a published set of uh mechanical properties and strength values. So there is a very clear path, but knowing that path and navigating it, that's something that Whole Trees has gotten quite good at and is not known by many engineers and architects. So it's one of the services that we're able to offer. I would say that rather than code being the barrier to entry for round timber, it is more a kind of historic bias against raw timber, that raw timber is unpredictable or variable when in reality, and also doesn't maybe look as clean-lined or machined as stealing concrete. In reality, it's a brilliant material. It's quite predictable in the way that it's going to dry as long as it's graded properly. And the embodied energy of round timber is dramatically less than sealing concrete. So we at Whole Trees are bringing as much awareness as we can to the ease and wisdom of using round timber in commercial construction.
SPEAKER_00And the greenness of construction, what's the best way to think about whether it's certifications or uh just the intrinsic beauty or the whole value chain supply chain sourcing of wood, what are uh say holistic and then easy ways to communicate how ecologically reasonable building with wood is?
SPEAKER_01It's a big question. When it comes to using wood in commercial construction, I follow the rationale of the mass timber industry that if you bring the stakeholders and decision makers into the decision early on, communicate why this is not only green and clean, but also uh can be cost effective if everybody commits from the beginning to design around the material itself. There are gratifying ways of making wood construction cost competitive to stealing concrete with tremendous lower embodied energy. There needs to be education early on and there needs to be commitment, despite, say, a general contractor's concerns about this or that. I think that looking at a project from its embodied energy perspective, which means um data-backed things like environmental product declarations, EPD, there are products that now that have very rigorous studies behind them demonstrating their level of carbon sequestration or embodied energy. And when setting that as the goal of a construction project to limit embodied energy as much as possible, decisions automatically turn towards wood. Um, so I suppose one way to answer that is to choose low embodied energy and high carbon sequestration as a goal of your project, and it will automatically drive you towards wood. Um, then you asked about maybe the micro reasons to choose wood. And of course, those are the fact that your whole nervous system relaxes when it's around natural materials. And I would argue with round timber, it is soothing on the brain and on the thought patterns and on our physical well-being to be around forms and shapes that remind us of nature.
SPEAKER_00I've never thought of it in that way. And I'm I'm in an office of round pole every day. And even when I'm doing work for many, many hours, it it definitely is soothing and very aesthetically pleasing to be in here. That brings me to the beyond the uh structural properties and the strength of wood and the ecological and climatic reasons for using wood. The aesthetics are pretty breathtaking of your projects on top of being functional. Could you tell us a little bit more, or maybe paint a picture if you could, on that front?
SPEAKER_01Sure. And I I tribute it to my co-founder, Rold Gunderson, who was on a 134-acre forest in Wisconsin in the 1990s, after having worked nationally uh as an eco-architect and thinking about this material, but through the eyes of structure and the eyes of a deep love of the shape and the form of the tree. So our projects all at their best harken back to the visions he sees when he sees trees reaching up towards the sky and creating their own structure to get closer to sunlight and closer to nutrients. They are buildings often have natural branching on the timbers that are used to hold up structure. So the columns, our columns, our branches at times bend towards and connect to beams. And um we hand peel our uh uh timbers or else just lightly debark and then sand in order to create like an undulating surface that still looks very tree-like and less machined. I guess I would say our structures are really an homage to the forest and to trees. And when you're in a building, it's a building product that's also rejoicing in the materials made from.
SPEAKER_00Absolutely. And I'm thinking about the branching patterns of coniferous versus deciduous species. Softwood, maybe a pine with two trunks uh having split off at the base versus uh maple or other woods that have call it more complex branching patterns, maybe from having some lateral sunlight in addition to just reaching up towards the sky. I'm curious what sorts of tree species you're mostly working with, or if it's a very broad array.
SPEAKER_01It is a broad array, and it depends on the application of the timber. If the and the design intent brought to us by the architect. If we are doing columns and the architect wants something expressive and dramatic, we will use hardwoods because they've their branching patterns, and often there are some species that have central leaders that create a straight column with branching patterns off to the sides. Those are really important to us when doing taller columns. If the application is for something a little more clean-lined, less dramatic, that's when our softwood sources come into play. Also, when we're spanning with uh beams, uh we often use softwoods. And when I say softwoods, we use red pine, Douglas fir, hemlock. These are regular applications, those are regular species for us due to one, the location of our facilities and two, the strength values of those materials. When we're using exterior applications, that's when we really get to promote the brilliance of black locust and white oak as excessively decay resistant, uh phenomenally decay-resistant species.
SPEAKER_00If we start with softwoods, I'm thinking about thinning a pine plantation, whether that's southern pine, red pine, white pine, etc. And a lot of the time you're thinning these plantations out anyway. And when there's a non-commercial thinning, it's more of a cost, and you're not, yeah, I mean, you're generating revenue, but you're not as a forest manager of any sort uh taking home profit from a non-commercial thinning. Would you say that uh thinning pine plantations for not small diameter, but smaller diameter round wood is really a large benefit to not just the plantation, but the whole wood economy, because you're just creating more value from these trees, these plantations, beyond just uh going to cardboard.
SPEAKER_01Well, ideally, yes. That is the vision. And yet it requires markets to increasingly demand these low-embodied uh energy, high carbon sequestering options like round timber. So thinning pine plantations for eventual mature harvests yields excellent structural material for construction. And it's the markets that need to catch up to the abundance of these smaller diameter thinnings. We at Whole Trees do purchase smaller diameter thinnings when the applications ask for it. And unfortunately, many times in the north, pulp markets have disappeared to the extent that these they aren't even being thinned. Pole plantations are left unmanaged until the price for an alternate use for land rises high enough and they're cleared and we lose our forest land. And so there is an unfortunate cycle away from forests because we need new markets like structural round timber for these stains.
SPEAKER_00We had a guest on from northern Argentina where they grow hybrid pine and uh eucalyptus and uh actually polonia as well, but mostly pine and eucalyptus in silvo pastoral systems where they just widen the spacing. And instead of planting a much higher number of trees, they'll plant fewer trees and then high prune them so that the light penetrates the canopy and they can have cattle underneath the trees. And with every hot day that cattle have access to tree shade, they'll gain 60% more weight. So it's it's super interesting to not just juxtapose uh a tightly spaced pine plantation being say undermanaged or unmanaged with something that is managed, but also look at so many other different types of I'll say forestry or agroforestry practices. I would love to see more silvo pasture systems like that uh in the in the eastern US, perhaps as we run the long-term financials for um really nice pruned saw logs and round pole, yeah, structural roundwood, in addition to just planting a whole lot of trees and walking away.
SPEAKER_01That is a vision. That is the right vision. We in our culture tend to think what do I need to do to scale this uniform thing over and over and over again on mass on larger and larger levels of scale? And in so doing, we wipe out balance in our own lives, in our ecology. And that lack of balance is now causing us global implications. What you just described is a whole different way of thinking of things. It says, How can I create prosperity and profit and balance, which I suppose is prosperity. That's interesting. So, whole trees, our vision is prosperity between uh forests and communities. And prosperity in our mind is profit plus balance, I think. I wish there was more reward in our culture for those who prioritize the balance of their economic choices. Um, what you just described in Northern Argentina sounds fantastic.
SPEAKER_00It's really breathtaking to walk through it and it's normalized there, which is there's a whole other story beyond or in call it normalizing plantation silvo pasture there. But it on top of being functional, it looks really good. Uh, they say that the cattle are the checking account and the trees are the savings account, or the trees are the 401k. So it's really just adding value uh to those rural communities. And so we could talk about pine for a while, but outdoor rot-resistant species or species for outdoor construction that are rot resistant are near and dear uh to both of our companies, Propagate and Whole Trees. And I would say our audience is very familiar with black locust Rabinia pseudo-acacia, but how do you usually describe black locusts to clients and what do you love about it?
SPEAKER_01We begin by saying that black locusts one of the top decay resistant species in North America that tends to hit home. Then we say that there are general engineering reports from the USDA Forest Products Laboratory, which is two miles from our headquarters, that document in service lifespans of up to 75 years for black locusts in ground as an exposure. To moisture. So we start right off with provable data back information because we know that in construction, the biggest concerns around wood in an exterior environment is decay. So if our audience is still listening, we then drop a little information about natural preservatives, the robinin, and how extracts from the species are also used in some termite prevention products. That tends to cause a little bit of a wow from our listeners, because again, another fear is termite. So I suppose black locust is fun to talk about because it addresses the fears people have about using timber and construction head on and in remarkable ways. It's such a unique material. Then I get to say that we are that at Whole Trees, and then also if you take my co-founder's body of work, we've been using Black Locust in exterior structural applications for over 25 years with almost no warranty issues. The warranty issues we point to are all stem from very early inexperienced uh selection processes before we knew the best grading practices for black locusts. So we have this body of work that grows every year with great proof of how to use this material and structure.
SPEAKER_00I end up comparing it to pressure-treated pine, but it's really a substitute for metal and stone, which is what you're highlighting.
SPEAKER_01That's a great point because it's not fair to compare it to pressure-treated wood. There's so many examples of pressure-treated wood failing in structure in a very expensive ways, because the industry has shared that, especially with southern yellow pine, pressure-treated uh glue lamb, or no, even poles, the material will last forever, but it really has a foreseeable and predictable end of life. Black locust really doesn't. So I like that. It's like a stone, it's also as strong as a stone and it breaks tools until you figure out the right tooling.
SPEAKER_00Yeah, you have to saw it when it's green, or else it's like cutting cement often. Yeah.
SPEAKER_01Yeah.
SPEAKER_00We put a decent amount of media out there, and one of the common concerns is that you just have to sharpen your chainsaw more often. And that's that's totally standard. You're you're just cutting a wood that's four times as hard as white pine, but it's also twice as strong uh in terms of first jank of hardness and then modulus of rupture. Yeah, douing tools is difficult, but building the same thing three times instead of once also takes a good amount of time and effort.
SPEAKER_01Yes, exactly. Well said. You have some good talking points that we should borrow.
SPEAKER_00I'll try and share a few. Yeah. It's uh well, you you got so many questions from folks that have used black locust. And I'm curious uh from a black locust sourcing perspective. It's an early successional species, so it often grows on abandoned farmland and land that say grew up into forest after being cleared uh 30 to 60 plus years ago. And in terms of sourcing black locust, where does it mostly come from? And do you see any leverage points in the black locust supply chain?
SPEAKER_01Well, as you and your audience knows, black locust is common throughout most of the United States. It's about having one's but it isn't a um scaled supply chain network. It takes some time and investment to develop a network of vendors and to train vendors into the kinds of specifications one needs. So that becomes part of a company's proprietary processes once they've spent enough time developing those networks. Um, I suppose someday as this material gains traction, it will have more standard supply chains and supply networks. Right now, we invest time and staff members into building connections, often with small landowners and foresters hired to manage forest lands. They know we need black locusts. And when they come to stands and spots where they're being asked by a managed forest plan to remove the black locusts, that's when we get involved and align our sales funnel or our speculative inventory needs with black locust being harvested. It's not a science yet. It's a mix of a science and an art, finding black locusts in the right locations in the country. Um, but we are getting quite good at it at Whole Trees.
SPEAKER_00And is there something that makes for a really good saw log for the black locust growers out there? Say if we're planting it, pruning it, harvesting it, making it happen, are there any common specs, even if uh the standardization is is not full?
SPEAKER_01Yeah. Um, I was thinking about this. Well, we don't we don't buy saw, I mean, we're not gonna saw them. So we're looking for exterior columns and beams. That's when we want reliable, straight black locust with minimal taper and twist. But we also sell to markets that include very playful markets like playgrounds, where the unique twisty, wobbly growth patterns are preferred. So we're often bringing to our black locust vendors the need for more branching, more branching shape, more unique form for our play markets, our play element markets. As for columns and beams, like I mentioned, straight with minimal eccentricity, minimal out-of-plane geometry, that becomes very uh useful to us.
SPEAKER_00It's very reassuring that you can use everything uh in terms of elaborate black locust from a growth form perspective and the straight poles.
SPEAKER_01Yes, yes, yes. And we are growing markets for that material. We're working with partners to grow markets for that material. Um, so it's exciting.
SPEAKER_00And in terms of diameter of black locust logs, we'll say eight inches and below can also be used for fence posts. And it doesn't make sense to mill a log that's less than, say, nine inches in diameter, mill that into boards. Are there certain diameters that are ideal for whole trees? I I would suspect you use the whole gamut of black locust logs.
SPEAKER_01We do, but when I think about columns and beams, the engineered um structures for our decking and our decks and our treetop walks or our pavilions and shade structures, black locust of eight inches or greater, and then a black locust that grows up to 18 and uh inches and 20 inches in diameter at its base, those remain very valuable to us, and we can offer a bit more in price than one can for a saw log. So yes, eight to nine inches is usable, especially as um beams and purlins, but the larger diameter becomes quite useful to us, and in that sense, I guess we we do compete with saw logs by paying a little bit more.
SPEAKER_00And you all just opened a new facility in Maine. Could you tell us a bit about that new facility?
SPEAKER_01Yes. In 2024, we uh officially opened a facility in northern Maine, Arusta County, that is envisioned as growing to four times the production capacity of our original facility in Wisconsin by 2028. There are strong reasons for structural round timber to have decentralized regional fabrication points. There is an ability to take advantage of the small and mid-sized forest economies when fabrication facilities are nearer to the source. And in Maine, we built a feasibility plan, we raised capital, we built out a growth plan, and we're finally able to turn the keys on this facility. It's a very exciting moment. We are leasing a reutilized hardwood mill that had closed down in the 2010s, and in that sense, adding a spark of revitalization to an area where forest products economy has been on the decline.
SPEAKER_00So, not just a dependable supply of white pine. You probably probably have a good amount of hardwoods coming in there.
SPEAKER_01I do not think we've even used any white pine. Yes, we are sourcing from all over New England. We are sourcing maple and hemlock, as well as cedar. There's a good number of species in Maine that we are sourcing, but we're also focused on black locust from New Hampshire, Vermont, and New York, and uh white oak from those regions as well.
SPEAKER_00And with black locust, do you think about a certain radius in terms of sourcing, how many hours or miles you'll have to truck it?
SPEAKER_01We are studying the cost. So we look for the closest black locust to our facility, and of course, black locust is not growing that far north yet. And our inventory management team is, I would say, almost constantly creating new connections in New England. So the first thing is what's the closest sourcing of black locust from ethically managed forest plans? Then we're starting to look at, well, what are the cost points? What are we paying per linear foot and how much more is added from shipping? And those things are part of the equation of what we purchase and what the market can bear.
SPEAKER_00100%. And I'm thinking about projects that are an excellent fit for black locust. When you think about all of the potential uses for this, would that's a great fit for say not just uh fence posts as a baseline, but large structural round timber outdoors. What are the different projects that have been arising, coming to mind in terms of planning and execution?
SPEAKER_01Yeah, the tip of the spear is outdoor recreation and play. There's a growing interest in North America and growing demand for black locusts in playgrounds, very um expansive and creative playscapes, etc. From there, landscape architects have started to look at black locusts as the columns and beams systems of shades, pergolas, the auxiliary materials in a park beyond just play. We are now specified into the next phase of the market that I think comes after park and play in recreation is hospitality. So outdoor structure that creates experience and tells story while also holding weight. Um so we're specified into different resort build outs that would like to be more sustainable and have materials that both transport the user and the visitor, but also last a great deal longer than conventional resort timbers that don't have the decay resistance of black locust. So that's the next market that we see as a tremendous opportunity for black locust.
SPEAKER_00Have you built any amphitheaters yet?
SPEAKER_01We do amphitheaters. The structural loads required for amphitheaters often have us transition from black locust to white oak. White oak is also decay resistant, not quite as much so as black locust, and yet grows bigger with larger branching structures. So our amphitheaters have had black locust, yes. But larger amphitheaters begin to transition into white oak, and then the spanning members, which are often covered, can be Douglas fir or hemlock or red pine.
SPEAKER_00With how long these timbers last, we'll be competing with the Colosseum in Rome, it seems like.
SPEAKER_01Oh, yes. Um we early in our lifespan at Whole Trees received federal funding to test the way that branching members move structural loads through their fibers and hold up weight. And we learned that there are ways to predict where a branching member will break and then engineer for the weakest point in that branching member. So that's how we bring branching members into load-bearing capacity and axial lateral structural loads. It's what creates such, I would say, whimsy and awe in our structures is bringing in more of the natural trees form and gesture by understanding how branching members hold weight.
SPEAKER_00Natural trees, form and awe, not just aesthetics, but structurally sound amphitheaters, so many ways to use these natural, structural round timbers outside. Amelia, thank you so much for joining us on the Plant the Trees podcast. It's been fantastic to learn about whole trees, and we look forward to perhaps growing uh growing you some trees in the next decades.
SPEAKER_01Yes, please. Um, we will work feverishly to create markets for those trees you're planting.
SPEAKER_00Perfect. Thank you so much. Thank you. A warm thank you to Amelia for joining us on Plant the Trees. If you'd like to learn more about Whole Trees, their website, whole trees.com, has a plethora of great information. I really appreciated the blend of engineering, ecology, and aesthetics in this conversation. Amelia and Whole Trees really pull together so many seemingly disparate but interwoven facets of the built environment. It's inspiring to hear about creating markets for healthier forests while also building spaces that genuinely feel good to be in. I really appreciate how Whole Trees helps people rethink trees, and especially species like Black Locust, and how they're capable of so many things in construction. I think I can speak for all of us at Propagate in that we deeply appreciate how Whole Trees helps folks rethink what trees and especially species like Black Locust can do in construction. We're excited to watch whole trees continue expanding and bringing more round timber projects into the world. For everyone listening, if this conversation changed the way you think about forests, wood, or building materials, don't you hesitate to share this episode with someone who would also enjoy it. Until next time, plant the trees and make it count.