This was our summer project.. A 16x25 cobwood barn. We plan on putting a small rocket-stove greenhouse in front. The warm attached greenhouse, plus the critters' body heat will hopefully keep the barn at a comfortable temperature for chickens, goats and an occasional calf or sick animal. The goal was to build the structure with the leftover cordwood from our house for as dirt cheap as possible. So far we haven't spent more than $500-$600 on it. We also experimented with a few new ideas along the way, using the barn as kind of a test project for load-bearing cobwood walls and a shallow sandbag foundation.
For anyone who's unfamiliar with cordwood building; you build with firewood sized pieces of logs (16" usually), you leave a cavity in the center that is filled with sawdust/lime or some other kind of insulation to prevent the cold or heat to wick right through the wall. Cordwood is typically done with cement, but we've chosen to build both our house and this barn using cob as our mortar for the sake of keeping this more natural and breathable (not to mention cheap!) We've not been disappointed! Cob is amazing!! :)
Cons: A big pain to get the roof somewhat level and safe to walk on. Hardwood pallets are heavy and defiantly bend each and every nail you try to stick through them.
Also, you will notice that the front of the building is sandbags with an earthen plaster all the way up. This is to provide more thermal mass in the south-facing greenhouse back wall, as well as give us more experience with earth/sandbag building.
Over the pallets, we put down a layer of old carpeting, then a pvc billboard tarp for a waterproof membrane. Another layer of carpet over the plastic for extra protection, and finally a layer of hay bales for an insti-green roof. I imagine we'll seed it in spring..
Here's how it looked this afternoon:
Still need to put some windows and doors on..
I found this project exciting because of how cheap it was, and it wouldn't take too much more work to turn it into a warm and cozy cottage! The roof was practically free, minus the billboard and some nails.
Anyway, just thought I'd share. Cheers!