When designing my cob house, it was a goal to keep building costs very low and to obtain as many building materials as locally as possible, especially natural (of course) and reclaimed supplies. Few materials were purchased new, and about as few are synthetic.
In this very detailed entry, Recipe for Building a Cob House, you can learn what it took to build my cob house for about $3000. You’ll also learn exactly how much cob I made (all by foot!), and specific amounts of material that went into the construction.
Please read ahead if you have any interest in building with cob!
Cob House Timeline
I started digging a foundation on April 19, 2008, and moved into GOBCOBATRON on July 11, 2009. I effectively worked from April to November of 2008, and then April to June of this year. In total, I estimate that I spent nine months working on my house, full time. I spent every possible day that I could working, except for when it was raining (which was actually very often in 2008), and except when I was traveling. I literally worked practically every day per week full time.
Batches of Cob in the Building
I stomped 219 batches of cob* for the walls by foot, with the help of over 75 work exchangers, visitors, and friends throughout the year. The cob bed and bench took nearly 20 more batches of cob, almost 1/10 of the material it took to build the house itself!
*one batch of cob is equal to three 5 gallon buckets of sand, and 2.5 worth of clay, nearly 30 gallons of material.
Cost Breakdown
I have kept close records of the costs of my building materials, and have determined that I have spent less than $3000 on building materials for the cob house. (I spent another $1000 on labor.) Here’s what I actually bought, and what I paid for my building supplies:
- sand (just over 30 tons total) – $507
- gravel (about 13 tons total) – $177
- straw (16 bales) – $36 (most straw I used was free)
- black walnut scrap lumber – $100
- misc. lumber – $20
- windows – $220 (two casement, one double hung window)
- electrical – $28
- galvanized wire – $30
- nails – $100
- raw linseed oil (for floor) – $72
- EPDM pond liner $622
- polycarbonate for skylight $400
and for the rocket stove:
- firebricks – $70
- flue pipe – $228
The two most expensive individual items are in bold. (Perhaps not surprising is that they are both part of the roof.) As you might imagine, many things are not listed because they were obtained for free – clay for cob, roof rafters, (hand harvested from our land and neighbor’s land), my large south window, urbanite for the foundation, etc. This is a very inexpensive house.
The total cost of supplies for the house is $3000. If figuring in labor costs, the house cost $4000.
Recipe for Building a Cob House
With $3000 for supplies and nine months of full time labor, I was able to build GOBCOBATRON, a small cob house with interior dimensions of roughly 15′x13′, and a footprint of (again, roughly) 20′x18′. Practically all of the labor was completed by hand (and foot!), including making and applying all of the cob.
It’s true… you can build your own home with little money, but with lots of time and enthusiasm. Extra hands never hurt, either! I can easily say that my Year of Mud was the most satisfying experience in my life. There’s nothing quite like the experience of building your own home with little more than your hands.
Gobcobatron Construction Slideshow
