Troglodium             Living underground


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Underground house

           It all started a long time ago (ZZzzz) looking for a way to build my own house, trying to find a different and affordable approach. Usually I found existing designs boring or unadapted for our climate. Then I fell on cordwood wall technique which seemed perfect for me, I got more infos on the subject and finally bought, cut and peeled the logs. That was in 1982.

          Afterward I had the chance to visit two of these cordwood masonry houses. It was a big deception due to bad designs and though I like the warm feel as an inside wall, I didn't particularily like the cracks all around the logs which would make our winter winds a dreadful experience. You can't get rid of these small cracks because cement after curing is inert and the wood expand or shrink depending the humidity levels that occurs daily or seasonally, the cement will not follow these cycles. One way to compensate for this is to caulk the outside cracks or cover the whole outside wall. 

             I was thinking about it all  when a friend told me about a conference in Montreal on earth-sheltering design. I burst out laughing, seeing myself as a neanderthal in a dark, wet cave... normal, normal..... but after a while the idea grew up on me and I finally realized that it was my solution. Went to Montreal (too late for the conference) bought all the books on the subject and withdrew for an intensive study. It abolished all my reticence almost manu militari. Made  my own plans (sketches) and calculations, went to an open minded local architect, got my calculations confirmed with very valuable building insights for a neophyte and well worth the spending.
             This two levels earth-sheltered home built with the cordwood  technique makes it an unusual, simple and cheap way to build, if you have time...  it is never strenous though just time consuming. That is why cordwood masonry walls will never make it to the usual contractors level but still ideal for DIYers. 

             It was the best for me in those days since the only construction experience I had was with sand castles. No joke.  Believe me no specialized skills necessary here if care, vigilance and still-working neurones are available. I will not go through specific how-to's of cordwood masonry here,  plenty of infos on the net. No internet in those days and my favorites books were ''Earth sheltered residential design manual'' by the Underground Space Center of University of Minnesota and ''Cordwood masonry houses'' by Robert L. Roy which is regularely updating his infos here.

            Engineers and academicians will restrain on such a proximity of wood and earth let's reassure them that in this case an elastomeric membrane will protect the wall from the earth just like an adequate designed concrete project. It is a pity that cordwood walls doesn't have official data and reference load tables.

             Located in southern Quebec, 300 meters altitude, temperate but still with some 2-3 weeks of scorching summer days with high humidity level and at the other extreme 1-2 weeks of cold days, around -30 degrees plus wind factors. The front of the house is oriented toward the south-south-west for passive solar heating. Dominant winds comes in sideways avoiding air-pressures and enough conifers close-by makes a  wind barrier in winter for the exposed wall.

              All building materials were recuperated, Douglas Fir laminated beams from a school demolition, oak flooring from a burnt down house, copper tubing for plumbing, aluminium windows from glass fabricant  which always has leftovers (wrong measurements...), doors, planks for sub-floor, studs for roof, bricks, sinks...everything....The big difference nowadays is that you are not alone anymore searching for those good & used materials, wreckers now sell at higher prices for what they were happy to get rid of... but it is still worth the search.

             Only the cedar logs I bought new, even then it was leftovers not suitable for shingles manufacturers and I paid a fraction of it's value. The transport did cost more than the logs! They were already quite dry and peeling them was a breeze, ideally they should be between 12cm and 22cm in diameter. Bigger ones will have to be split and the look isn't as good. Too small will need more cement more work and more costly. I used cedar because it is common, putrescent-resistant, has good density, long fibres and a better response to humidity variations than hardwoods. Other similar types of wood would do too.

             After all those years what I liked the best is the aesthetics of it and the comfort zone  which is phenomenal,  your energy needs to cool or warm up is diminished roughly by half.  In wintertime around here the earth will freeze down to more than a meter below ground level, so even if it's -30 degrees outside you will only heat against roughly the freezing point. If you get down enough the temperature would be stable all year long! But that is too deep for our purpose. Same for summertime, no cooling system needed for those scorching days and hot nights. I use the same coverlet all year round !

              On sunny days at -30 outside I open up the door around 1 PM because it gets too hot inside and to ventilate thoroughly, the low winter sunrays combined with solar passive will immediately compensate, to the neighbor's amazement.  Be it -5 Celsius or -25 Celsius outside the heating needs are barely the same, most heat losses due to the front wall and its windows.

              Remember that the more snow on the roof the warmer will be the house, snow is a great insulator.  I never mow the grass on top, it helps to retain the snow and in summertime it keeps the sunrays from overheating the earth mass around and on top of the house. Be aware that extra snow loads can be critical in springtime or in wet snow condition which is another design parameter.

             Some habit changes became obvious after a while, like expulsing the cooking, showers humidity at the source (just like any tight envelope building) and in summertime opening windows at nightime instead of daytime where the air is too hot & humid causing condensation on the colder lower floor and lower part of the wall. Problems resolved with adequate ventilation timings. But still in some high temperature and humidity level period  some mechanical dehumidification is preferable once a while. A ventilation system with heat exchange and humidity controls could be considered. I go by without any.

             Back in 1980's earth-sheltering was innovative, avant-garde and promising but it didn't catch on. It is still at the same point on the friendliness barometer, it is still seen as avant-garde !!?!! 



Western side

Workshop & 2 levels home

Acoustically perfect

Beams and beams

Easy to build