Building An Earthship In Darfield, B.C.

We are a family of five living in Darfield, BC.
Our house is six hundred square feet in total and we are feeling cramped.

We have decided to build an earthship!

So starts the adventure ...

Wednesday, November 26, 2008

Composting and an Earthship

So ... other than the fact that I like the smell of compost (and Katie apparently does not), what possible tie in is there between an earthship and composting?

One of the principles of earthship design and living is food production within the building envelope. We have only just started wrapping our heads around the idea of a greenhouse being part of the living space. In principle I completely support the idea ... in practice I have only read about it.

We are neophyte gardeners. We just planted our first garden this year (a square foot garden), and we were reasonably pleased with the results. It took me a while to accept that some plants are going to die no matter what you do, and the quickest solution is to tear them out and replant!

We did spend a fair bit of money on store bought compost this year and we do not want to repeat the experience as we fill our planters in the house after it is built. I have embarked on an aggressive composting regime to make sure we do not!

I built a 3 bin composter (pictured above) this spring, and have been experimenting with it for the last seven months. The idea in this composting is to create large piles (minimum of 3'x3'x4') of layered compost. The compost pile is supposed to heat up (anaerobic composting) and composting should proceed fairly quickly. The more often you turn and mix the pile (hence 3 bins), the faster the composting should go as the material gets uniformly mixed and oxygenated.

A month into my first pile I turned it and discovered I was not watering enough. Some of the material in the pile looked as fresh as the day it went in. When I turned the compost pile over I had my son Stephen hosing down the pile continuously (this is the perfect job for a nine year old boy).

Our kids were in 4H (an agricultural youth club) and in August their sheep, and all of the other kids' sheep in the club, were sheared. I learned at the shearing day that all of the wool went to the local dump, and I could not pass up the composting opportunity. Consequently, at this point I added lots of wool, hay and sheep manure to my compost piles. Also, when I turned the piles this time they smelled wonderful (for a very short period of time). Wet compost seems to do the trick, and I cannot say that I have overwatered my compost pile yet.

Not many people think I will do well composting the wool. Experienced sheep ranchers claim that they have seen many year-old-piles of buried sheep wool look almost as good as the day it was buried. I added lots of water!

The image at the top of the post is me turning the piles last week. I had noticed that the piles slumped quite a bit over the last month, indicating that composting was occurring. When I turned the piles I was amazed. It was below freezing that day and steam was pouring out of the pile as I dug into it, and it was very warm. I did not measure the temperature but I know I have active composting! The sheep's wool also looks like it is breaking down nicely. The round drum in the right side of the picture is a tumbling composter that Sandra obtained from FreeCycle. It seems to work quite nicely.

By far our most expensive purchased compost this spring was worm castings (over $20 for a 35 litre bag). I used to keep a composting bin of worms, but had stopped about five years ago. This summer I bought 2 pounds of red wrigglers at $35/lb (ouch). I tried to pick up where I left off five years ago, but things did not go smoothly. I almost completely killed off the first 2 lbs by overloading the bin with compostables too quickly. I think the compost went anaerobic (i.e. hot) and essentially cooked and dissolved the worms (it was not pretty).

Discouraged and humbled I went back to the worm supplier and got another pound of worms. Raising worms and making my own compost was not working out cost effectively. I built the worm population up over the last six months in two commercially available composters that I owned (a wriggly ranch, and a City of Toronto worm compost bin from our Toronto years), and last week I added a third much larger composter that I built to the mix. If I can keep this up I should have plenty of worm castings this spring.

In the back of my head I have been thinking of integrating hydroponic food production into our earthship's gardens. Rather than have an inside cistern, I hope to use that space as a fish pond (say tilapia). My thinking was some of the fish food could be worms! I do not know the practicality of this idea, but I was just reading about an earthship called the Pheonix that is designed to use this approach, so maybe this idea is not as half baked as it seems to me!


Joseph Beckenbach said...

"Greenhouse" *in* the living space. Hrrrm. Wouldn't this be neutral at best regarding heat, unless you thermally isolate it from the rest of the house? And can the rest of the house handle the extra humidity, dirt, and need for ventilation?

Grandfather Beckenbach's house could not, so his beloved orchids thrived in a greenhouse thirty feet out the back door.

Some of the permaculture materials I've come across seems (to me) to suggest that attached greenhouses are suited only to warmer temperate climates. Even with the Solar-Slab added into the mix, Kachadorian notes attached sunspaces can't be justified on day-long average thermal benefit. (Insulated, isolated from the main house at night, perhaps justifiable -- run the numbers.)

Perhaps a local architect can assist with making that decision?

-- Joseph (son of a retired architect)

Joseph Beckenbach said...

Other ideas prompted by the rest of your article:

Find local spinners and weavers! Raw wool can be great barter material. It's also great insulation.

Lots of good material about composting and small-input gardening / micro-farming through Bountiful Gardens in Willits CA. They've been refining the "Grow Biointensive" method for three decades now. +1-707-459-0150 Their "How to Grow More Vegetables" is a great basic book for a food-producer learning this method. Composting and soil fertility is emphasized.

A friend of mine in Alaska has worked some with tilapia and their water-tanks for food production and heat storage. He's figuring out a closed ecosystem suitable for long-term human use, such as would be required in a Mars base. If you have specific questions, I can relay them and get you two in touch.

One issue I had with earthships (given what presentations I saw, quite some time ago) was the emphasis on producing food within the structure, whether or not that made sense in the larger system of house plus land. Between cold-frames and green-houses, one can get more productive area going on around the structure than is in a structure. (BTW, Mollison and Mia Slay, "Introduction to Permaculture" 2nd edition, ISBN 0-908228-08-2 notes that cold-climate areas which choose to use greenhouses need to close off from the rest of the house -- thermal considerations, apparently, and there's suggestions to use water-tanks for thermal mass within the greenhouse itself.) I suspect the earthship concept has refined to address this concern since I last looked at it.

-- Joseph