Why Whole Trees?

GUEST POST BY DELLA HANSMANN

If you’ve been following this blog for a while, you’ve seen the term “whole trees” a number of times.  Doug and Denise have decided that they want their new home to be a whole tree house.  They won’t be living in the air, however.  Here’s a little explanation of what we’re talking about when we describe their new Whole Tree Home.

Branching columns in the Bookend House at Driftless Farm

Branching columns in the Bookend House at Driftless Farm

Whole Tree buildings are timber frame structures which use un-milled trunks and branches of trees to make up their structure.  Why do such a thing? 

Whole Trees are High Tech

carbon nanofiberThink about it: you know how steel is smelted and how plywood is glued together but how is a tree manufactured?  As my boss likes to say, “Whole trees are a self replicating carbon nano-fiber comprised primarily of air water and sunlight.” The building material of the future, don’t you think?  No nasty by-products, no off-gassing period, no health risks.  In fact, the process of “manufacturing” a whole tree component is to photosynthesize our collective carbon emissions into nice clean oxygen.

Whole Trees are Strong

tree stressWhole Trees are naturally pre-strengthened as they resist the force of the wind trying to blow them over.  When trees grow outward in rings, each new year’s growth acts like a tension sleeve which holds all the fibers together and makes them strong.  When you cut those rings to make standard dimensional lumber or even heavy solid beams for a conventional timber frame structure, you slice through all of those strength giving rings. Structural testing at the USDA Forest Products Laboratory has determined that a round timber is %50 stronger than a milled piece of lumber with the same cross section.

Whole Trees are Tested and True

Whole Trees have been around the block.  Trees have 200 million years of structural testing.  They’ve been tested in some fairly long lasting construction applications too;  a wooden building can last over a thousand years if built well and maintained.  There are many standing Nordic Stavekirkes (wooden churches) and Buddhist temples still in use today.  In the United States, several National Parks buildings built of round timbers have stood for over a hundred years.  Heavy timbers, both round and milled, are a particularly strong, safe building material.  They less likely than conventional stick-framed buildings to be damaged in a tornado or earthquake.  In a fire they are much safer.   Fire in a steel building causes the beams can columns to expand and break their connections.  Stick-framed buildings create natural chimneys in the walls which channel fire from floor to floor.  But a timber structure will char, forming a protective layer that keeps the fire out of the columns and beams and keeps its structural integrity.

a buddhist temple in china, a stavekirke in norway, and the old faithful inn lobby

a buddhist temple in china, a stavekirke in norway, and the old faithful inn lobby

Whole Trees are All Around Us

Further, most milled lumber comes from old growth forests and monoculture plantations in the Pacific Northwest, even from as far away as China.  It requires large trees that are clear cut for ease of access.  Keeping the structure of the tree trunk and branches intact makes them stronger, allowing us to choose smaller, younger trees for our buildings and leaving the old growth in peace.  The benefits of this are manifold.  We can use younger trees, which can be re-grown more quickly.  We use trees from the area, sometimes even from the building site, rather than shipping them from across the country.  We use a greater portion of the tree since we don’t necessarily need the straight center of a tall trunk to get a usable building component.  And we are able to harvest selectively, choosing several appropriate trees from an area and leaving the rest of the forest intact. 

The result is a building material that requires much less energy to procure and even protects sequestered CO2 and holds it within the building.  Unlike old growth lumber, whole trees are an easily renewed and accessible resource that is available from the small woodlot of nearly any Midwestern farm.

Whole Trees Keep Costs Local

Whole Tree Construction and other Natural Building techniques keep your money local.  Think about it – when you build a house these days you are paying a certain amount for local labor, but how much of the rest of the cost goes to local materials.  Where do the 2 by 4s come from; the plywood; the trusses in the roof; the pre-painted vinyl siding, the asphalt shingles for the roof?  All of those dollars are leaving the community you should be supporting.  Whole Tree construction keeps a larger portion of the cost of construction within the local community by both reducing the amount of imported materials and increasing the use of local labor.  Why not make the construction of your home an investment in your home economy?

local labor breakdown

What’s not to like?

Whole Tree buildings are not only beautiful and aesthetically pleasing but they are strong, safe, environmentally friendly and economically savvy.  I also believe that they are a vision of things to come.  Our housing choices are going to change radically in the next few years and decades as the rising cost of energy makes the current model of conventional construction as economically unfeasible as it is environmentally unsustainable.  Follow this link for some thoughts about the future of American housing from Christopher Steiner’s new book $20 Per Gallon: How the inevitable rise in the price of gasoline will change our lives for the better.

If this all sounds like a sales pitch … it is.  I want you to build a Whole Tree house, too.  But hopefully someday soon you won’t have to come to my architecture firm to get one.  With a little construction savvy and a small woodlot you can already use the forest in your back yard to make your own whole tree garden structure or gazebo.  At Whole Tree Architecture and Construction we hope and plan for a time when this amazing building material has really taken off and people all around America and all around the world are able to work with designers to make their buildings out of natural local materials that they have a direct connection with.  To find out more about what you can do with branching columns, check out our website www.wholetrees.com.

the bookend house at driftless farm and attached greenhouse

the bookend house at driftless farm and attached greenhouse

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7 replies

    • That’s a good question!
      Our builder, Whole Tree Architecture and Construction, uses whatever trees are readily available in the building area. That’s the beauty of this approach. We chose the trees for our house by walking our woods and looking for those trees that were compromised or compromising others. We had a dual purpose of gathering building material and improving the health of the forest.
      We will be using mostly oak, elm and black walnut for our timbers, although our architect has had good luck with “weed” trees like buckthorn too. Because we have some planted conifer stands, we are using pine and spruce for the rafters.
      Whole Trees received a federal grant to work with the U.S. Forestry Lab to test the strength of branching members. The numbers are being crunched now.
      Using unmilled timbers would be a great way to manage the many degraded woodland areas we have throughout this country because the process is so flexible.
      We will be breaking ground in a few weeks, and then the whole-tree timber frame will start to go up. I’ll be publishing posts with lots of photos throughout the process. I hope it will be helpful to you.

    • Thanks for your kind words.
      My husband and I get the wonderful benefit of living in a beautiful, efficient, comfortable house, but our real goal was to build a house that would spark ideas in others as they consider building a home – to step away from some of the more wasteful, nonsustainable approaches in standard building practice.
      It’s not necessarily more costly and it’s much more cozy.

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