Modular CEB Construction

Meet Scott – who is now here on his Dedicated Project Visit, focusing on preparation for CEB construction. We are evolving a Modular Building System based on CEBs, the next fork after our initial directions.

Hey everyone,

I been here just over two weeks now and I am becoming more and more comfortable with the daily happenings and challenges on this old soybean field. I have not properly introduced myself to the OSE on-line community yet and I would like to do so through this short video, which I made before arriving as part of my application. I first heard about Factor E Farm through Juliet Schor’s Plenitude, her introduction to Marcin’s work provoked enough curiosity for me to come volunteer for a month. My work here has focused primarily on laying out the foundation and building the roof trusses for the CEB workshop coming soon. I have also helped in the garden and with the canning and storing of various food items. Working with Will and Marcin has been a fascinating learning experience, especially considering I barely had a grasp on the phrase “open-source” before arriving. Now, I write to you from a newly installed Linux operating system in dual boot Linux/Windows!

In this post I want to primarily update everyone on the CEB workshop progress, including our ideas and hopes for the final design. But I also want to speak about life at Factor E Farm from a volunteers perspective, providing insight for others who to want to come for a Dedicated Project Visit.

In two weeks (right when I leave unfortunately) we will begin construction of a building which will allow us to accomplish three goals. First, it will allow ample space for the increased production of our first two product releases: the Liberator and the LifeTrac (release planned for May 1, 2011). Second, it will provide us with inexpensive, modular, and replicable living/work units. And finally, and most importantly, it will give us the opportunity to demonstrate Compressed Earth Bricks in action.

Workshop Model

The Google Sketchup file that can be downloaded here gives a cross section view of our workshop to be. It will consist of fifteen 16’x16′ units (256 square feet), ranging in height from 10ft to 14ft, with each unit housing a different piece of machinery such as the open source CNC Torch Table, the open source Induction Furnace, or the open source Lathe – with ample space around for ergonomic design. The middle path will be open to drive a vehicle through in order to move heavy parts being manufactured (and because it is being built over our driveway!). At the corner of every unit will be a 2’x2′ column of CEBs, these will support the roof. The walls of the structure are flexible to our needs. We can produce an open air structure, a greenhouse, or winterized straw bale with easy fill-in of hammermilled strawbale. I have finished building the roof trusses for this structure, and documented their construction on the wiki. Further documentation of the CEB Modular Building System is also started on the wiki.

The exciting feature of these work/living units is their modularity and the ease of replication. Using earth and wood (next year) from the farm, we can quickly build a structure for our needs. Our design easily accepts additions, allowing us to expand the size of our structure. Soon we expect to have a kitchen, bakery, and bunk house all from this same basic design. As we build the structures we will be updated everyone on the costs. So far the roof trusses for one unit total $250. Other expenses we expect include the sheet metal roofing, cement foundation, floor, steel angle brackets, and any non CEB wall additions such as greenhouse glass windows. In the future we expect the wood to come from the property and to be able to produce all the metal components from scrap steel, greatly reducing our costs. We are not aware of any other modular masonry building system (outside of bricks themselves), but we are aware of the work of CMPBS on GreenForms, a modular building system based on wood posts, and other similar work and concepts such as GroHome.

The basic modular building unit consists of 4 CEB columns, 2’x2′ thick, in a 16 foot grid. This allows infinite modular additions to be made, and the roof can also be extended. Walls can be built to suit whatever purpose is required, from home to workshop to greenhouse to chicken house to luxury suite. Insulation can be filled in wall and roof cavities. There are practical details to consider to make this work, and so far, we think we have them covered.

When I first arrived I was a bit disappointed with our cookie cutter design of the modular CEB units, picturing a suburb of mud homes. Personally I have spent hours building beautiful structures from clay, manure, sand and water mixtures. I enjoyed the aesthetic freedom it provided, the feel of the material on my hands and feet, the sense of community as we all jumped on the daub together. But I also remembered the time it took to build, the number of people needed for efficiency, and how the smell of poo stayed on me for days. I have come to the conclusion that we need both of these styles of building, assuming both are sustainable and community oriented. But we have places all over this world trying the latter, and only a handful focusing on replicability and modularity. This IS an important project. With a tractor, CEB press, and saw mill which you can build in your garage, earth and trees from your land, and only a smattering of external materials (which we are working on creating), you can build a simple home, not extravagant, showy, or huge, but able to fulfill your needs. (Although with the hole from the earth you can have a pool…aka pond.) This brings us one step closer to freedom.

This has been an exciting project to design and begin construction of. The implications of this work are far reaching, especially in reducing poverty and our reliance on off-site materials. Needless to say I will be checking the blog in the upcoming months looking for key updates.

It has also been exciting to see the day to day operations of Factor E Farm. For an on-site project three years old, with only a smattering of hands involved, and funded solely by readers like you, the amount of work accomplished here is impressive. From caring for the plants and animals, to preparing food, to updating the wiki and blog, to building, inventing, failing, succeeding, collaborating, learning, brainstorming,…it can be exhausting! But the uncompromising belief in this experiment and the amazing support we receiving from seemingly random people the world over is rejuvenating.

Still life is relaxed here. There is no pressure, no hard dead lines, no micro-management. If you need a day off, take it; if you see something that needs to be done, do it; if you want to go fish, then go and feed us. The expectations are that you know best what you need to accomplish a certain task, if you need help seek it out, and do everything to OSE standards. Bring with you passion, personal motivation, and love for independent (and group) problem solving. It is a surprisingly simple life here; everyday I find personal time to play the Ukulele, watch half a documentary, or call family and friends.

Unfortunately I am only able to donate a short month of my time to this project, but I hope to return in the future. I want to see the apple trees taller, the soil healthier (damn mono-culture!), Marcin with some free time (haha!), and of course a fully functioning construction set ready to create change.


Scott Gallant



    To anchor trusses to top of ceb columns, you might break the ceb by driving the rebar into the top of the column especially if the block has set up and gotten hard. what about preforming the rebar and putting it in place as you lay the last courses of block? To really overdo it for tornadic winds you could start by bending the rebar in the shape of a giant staple that could straddle the truss and extend down into the ceb post. the head of the staple would be just wide enough so that the legs would fit snugly against the sides of your 2.5 inch wide truss and help stabilize it against side-to side wobble. (wooden shims could be used for fine control of the fit). The legs would be long enough to extend down opposite sides of the truss, say 2 feet, plus another 2-3 feet into the top of the ceb post. you could even bend the last 3inches of the leg out to horizontal like they do with anchor bolts that are set into wet concrete. Downside to this method: careful placement of the rebar so that there is enough space to accomodate the height of the truss between the top ceb and the bottom side of the staple head–but you might also get around this by using shims.

    I like the idea of chopped straw insulation for the ceiling. have you thought of spraying it with a dilute, pH neutral solution of boric acid/sodium borate as a fire retardant and insecticide? (would need to let it dry out of course after spraying)

    When I retire a few years hence, I want to build residential for folks trapped in the rental cycle. You have some good ideas I’d like to borrow. A big issue for residential, however, is how to insulate and finish the exterior walls in some sort of conventional-looking fashion for a wet climate (east Tennessee). Any suggestions on that?

    1. Marcin

      The latest on truss tornado-proofing is to drive a piece of rebar, horizontally, through the 2 foot wide column. Then, hang tie-down strips to the trusses.

      Tell us more about boric acid/sodium borate and where to source the ingredients.

      On outside finish for wet climates, outside of overhangs – one could simply use paint. To have a conventional look, one could wet and smooth the surface to perfect flatness, then simply paint. A texture sprayer could add texture to make it look like stucco.


    Horizontal rebar—great . thanks

    Have you decided how to insulate exterior ceb walls?

    ON borate: if you google for “borate wood preservative” the first page gives several commercial products (BOR-RAM Wood Preservative, Timbor Insecticide Fungicide Wood Preservative , Bora-Care Wood Preservative, and some informational sites that include diy iinstructions (…/Recommendation-for-Borate-wood- preservative-product-385918-.htm ) I have used both commercial and homebrew borates in my stick-built house. As I recall the homemade stuff is about half the price of the commercial because it uses borax from the grocery store, borate from the hardware store, and antifreeze from the auto parts store. I prefer the antifreeze-based mix because it penetrates better, even though we had to cook the water out of the initial mixture on an outdoor camp stove.

    Some of the google sites address a recent improvement by combining silicates with borates but i have not followed up on this yet.


    OOPS–on re-checking I found that you are planning to use chopped straw insulation for the walls. Hmm—a double wall of ceb, so will you tie them together somehow? Hay should be cheap and plentiful but what about moisture/mould/rot/ critter problems–both from the ground and from the exterior wall? Will you run plumbing and electric in the hay?

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  7. John R

    If I want to go find the building codes for a structure like this what would I call it? And what codes do I need to look for?

  8. Zach Dwiel

    I was able to go to our building department with the New Mexico building codes and use them:

    Otherwise, you might be able to use code for adobe if your jurisdiction has that