Information Wanted About Cob Houses in Cold Climates

by ziggy on February 27, 2010 -- 16 comments -- Follow

This is a call for information from folks living in cob houses in cold climates – by cold, let’s say places that frequently have below freezing temperatures in the wintertime. If you live in a cob house in an area with cold and/or extended winters, can you describe the construction of your home and your heating system?

How thick are your walls? Do you have any insulation (in the roof, stemwall, floor, etc.?) What is the square footage of your space?

How are you heating your house? How often do you run your stove? Is the home occupied full-time during winter days?

Finally, can you provide average indoor/outdoor temperatures? How comfortable does your cob house stay?

I will followup with some insight into winter conditions in my cob house in the near future.

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  • Doug

    I am very interested in the answers to these questions as well, as some friends and I are planning to build a cob home in central Ohio. I’m pushing for a bale-cob north wall to improve the insulation, but I think I’ll probably be outvoted.

  • john

    Since you are looking into these questions I have one for you. Have you thought about another rocket stove to be used for radiant heat. You have heard of radiant heated floors, why not run your pipe 12 inches under your floors. Set it up right the first time, you should capture a lot more of the heat made available from your pipework by use of radiant heat. Good luck on your answers, JOHN

  • Hullo, brave pioneers! I am so inspired and intrigued by your work. I, too, find myself settled in a rather treacherous climate (Well, the Midwest does have some rather ugly winters), and I am TERRIBLY curious as to whether it would be possible for a single Mom like myself to somehow gather the information and resources to accomplish such a grand undertaking. Creating a home for myself and my growing boys seems altogether too wonderful, but your blogging brings it into the realm of the possible. Maybe. Or does it? I’m afraid to hope, really. But I will be watching… and dreaming. 😀

  • I read your post about the rocket stove which is highly educational since I have not yet built one but am planning on it.

    I have a comment/question/suggestion. Do you have any insulation on your home? Cob/earth structures are great for thermal mass but suck at insulative value, i.e. they’ll soak up heat but they won’t hold it for long. If not, you should really consider adding some. Since you have the structure finished, perhaps you could add a layer of 8″, 10″, or 12″ earthbags filled with scoria, rice hulls, or peralite on the exterior of your cob structure and then cover the earthbags with cob again.

    Just an idea I thought I would share. I am in the planning stages for an earthbag house with half the bag filled with clay/dirt and the other half filled with the insulation material. I plan to cover the whole house then, instead of with cob, with Magnesium Oxide Cement, which is waterproof and earth friendly.

    Good luck.

  • paul

    Abbie, you might be surprised. the impossible has this funny way of losing its prefix. 😉 i am currently in MN and will be taking a complete cob workshop at Cob Cottage Company in May (oh my goddddddd that’s so soon!!!!), and after that… well, who knows? i get the feeling that i’ll be itching to put that embodied knowledge to use in whatever form arises.

    i’m really looking forward to seeing the answers to these questions, Ziggy. my wife and i have been contemplating whether staying in the upper midwest near our families to build cob will be environmentally/economically feasible or if we ought to follow our hearts elsewhere and settle where winters are less bitterly cold. we’ve fallen in Love with parts of OR and NC, discovering the needs a MNcob would have will be so helpful.

    Thanks for providing such an inspirational resource to us all, Ziggy!


  • KarenJ

    I understand that there is a cob structure at Dufferin Grove Gardens in Toronto… and that’s north of Detroit, so… Here’s a link to pages about it.

    I live in Nova Scotia, and am looking at a heavy freeze/thaw cycle — with humidity etc… so am wondering. This weather takes it toll on asphalt, I can only imagine clay…


  • Luke

    Hi.. I’m sorry at start for ma english, is not fluent. But… I come from Poland, where we have very cold winters, this winter for example -30 C …I’ve seen traditional cob houses in forest. The Wall is usually about 80cm width, with some straw under clay plaster. Well Insulation is the most important. I hope its gonna wor properly with some external insulation to keep warm inside house…
    good luck…
    PS. Thanks for inspiration!

  • Hi,

    we plan to build our own cob house ( in northern germany where it’s sometimes cold in winters. Even though it’s about the same geografical langitude as Great Britain (where there’s a long tradition of cob buildings) our climate is slightly colder. There are next to no cob buildings here – traditional or otherwise. Yet 😉

    So it’s very interesting what you write, Luke. Do those buildings you found have cob walls with exterior straw insulation and then a layer of plaster? How is the straw insulation kept in place? How thick is it approximately?

    Does Ivy have an insulative effect if it covers the walls? Does anyone know that?

    Love, Meeresbande

  • Mike

    Great site.
    I love the spirit of your (ongoing) project.
    My wife and I have been toiling away for 4 summers on our place. We started out in a tent, hauling in water in jugs, and cooking on a shitty woodstove. Since that time we’ve stepped it up a notch with a second-hand yurt. Things have been slow (thanks in part to our ever-expanding garden), but the cabin (425 sq ft) should be done soon. Winters sometimes hit -30C (yes you read that correctly) where we live, so we’re also wondering how our place will perform. We’ve gone bale-cob on the north and west walls, cob and cobwood on the others. We decided against the rocket stove (after spending a couple of years scrounging materials) and, judging by your ordeal, I’m glad we did. We’re insulating above the ceiling with wool and straw-clay. If things get too cold, I figure we’ll have to invest in wool blankets and try to do as little as possible during these periods until we can build something better.

  • Hey Mike: I’d love to hear how the balecob is working for you.

    I still think rocket stoves are great, when they work well. I would like to try building another one day…

    Leona: I can’t imagine ivy would do much in way of insulation.

    Luke: Can you describe the “straw under clay plaster” some more?

  • Mike

    Hey Ziggy,
    As for the thermal performance of bale-cob, we won’t know for sure until we move in. At the moment I think it’s a totally sweet way to go. Cob is slow going, especially when you’re mixing solo, and throwing bales on the wall is amazingly uplifting. Bang, bang, bang…as easy as tossing bales on the wall, checking to make sure they’re plumb, and spiking them down (we use bamboo). A cool feature of bale-cob, because the bale twine faces out, is that you can easily bend the bales with your knee. This means you still maintain a fair amount of sculptural freedom. The main consideration when building a foundation is to make it wide enough to accommodate a bale and 6 inches or more of cob. We tend to freelance a bit too much and weren’t able to use bales in places because the foundation was too narrow. The CobWeb devoted most of an issue to Bale-Cob a few years ago and it’s well worth picking up.
    I agree that rocket stoves are still great, and Ianto makes it very clear in the book that there is much experimenting to be done. Who knows when we’ll get to it, but the plan is to build a propagation greenhouse and put the rocket in there. Endless projects.

  • Jeremy

    I’m sure you are aware but earthships answer this question best, IMO. My wife and I are planning to build an earthship in Nevada, northeast to be exact, and there long, cold winters there. Passive solar heating and an insulated thermal mass are the best solution. You COULD use these techniques on what you have already. You could surround your walls with a thermal mass. As for passive solar heating, since you have a cob house you may consider a solar can heater. You can make it yourself very easily. Check out this site.

  • rob

    cod house like to know more in the cold i live in michigan u.p. and it gets cold

  • solua

    I live in quebec canada where the winters are pretty cold and temperatures stay below freezing for months. I have built with cob in warm climates but I am planning to build my cob shelter next year up in the great north… I think I will use a french method called ‘torchis’ on the outside of the walls, as thick as it needs ! And I will sink the northern face in the hill. Now the key to holding your heat in this kind of weather is to have a radiant cob floor that you could heat in many ways…even with biogas from your toilet, or a rocket stove perhaps !!!
    Bioshelters would also be part of the design, considering they have so much to offer, and you would probably orient your windows and all in the most passive solefficient…. so there is always an heat exchange in your cob mass.
    Big thick walls and benches where the sun shines in winter, and you’ve got yourself quite a cozy shelter…
    Some people go cobale hybrid because they focus on insulation, I think that with clean and efficient ways of heating you can be comfy.
    The dream is to sculpt and shape your house so why not cob it all the way and stay in the magical realm of cob !!!

  • jennifer

    hello all, i am thinking of building a cob home in north louisiana on property my hubby and i own. i have done alot of research, and feel prepared. my only concern is i know of no other such home in our humid, southern climate having been built. i know they have been built in rainy, cold climates w/ success. i hope my fears are for not. hopefully us southerners just haven’t tried it yet. is our hot humid climate anything to worry about? or will i just have to be the first to find out haha?

  • Jennifer: I can’t offer you any tips on where to get info., but I can say: ventilate, ventilate, ventilate! We are in a similarly humid environment and mold is a major concern here, but if you can keep air moving in your home, mold will have a much harder time getting established. Think about having vents placed low to the floor and high up in your walls to keep air moving all throughout your space.

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