Maybe living in a \\\\\\\"hobbit house,\\\\\\\" or cob house, has never occurred to you. But have you ever considered living in a non-toxic, beautiful, natural building you can construct yourself, often for very little money?
Photo credit: "Yes" Magazine: How to Build a Cob House
Maybe living in a "hobbit house," or cob house, has never occurred to you. But have you ever thought of living in a non-toxic, beautiful, natural building you can construct yourself, often for very little money? Welcome to the world of cob houses.
Earth Building Movement
Various types of earth building movements have emerged in the last few decades. Natural building techniques including cob houses, earthbag homes, earthship homes, yurts, straw bale houses and rammed earth construction are becoming increasingly popular. Many use similar materials, but with variations in technology and earth building techniques.
Along with earthship homes, yurts, earthbag homes and other houses using natural building processes, cob houses stand out for their aesthetic potential and durability. Cob houses are admired for their sculptural quality; since they employ earth building techniques using the same principles as fine art sculpting, they can be molded into virtually any shape.
What is Cob?
Cob is a mixture of clay, sand and straw. Sand is the ingredient in the cob recipe that gives cob house walls their strength, while straw acts as reinforcement and clay holds it all in place. Molly Miller of "Mother Earth News" provides the following proportions for a general cob mix:
The Cob Recipe:
50% to 85% sand
50% to 15% clay
straw to taste
Adjustments may have to be made for local soil variations.
Cob House Costs
Cob houses can be built cheaply because the dirt can come from the land on which you're building. But if you must have sand and straw brought in, costs go up. Also, if the earth you're digging into is hard, you may have to rent digging equipment. This also adds to construction time, which is already fairly long. It takes time for the cob to harden sufficiently to create solid, sturdy walls. However, many cob houses have been built for $5000, and some for as little as $1000.
Cob houses are generally much cheaper to heat and cool. The walls are thick and well-insulated, and contain no toxic materials. Learning passive solar design principles will help you maximize the energy efficiency of a cob house. For example, placing an angled window to the south helps trap the sun's heat in the walls to be released into the home when temperatures drop.
Cob House Built-Ins
You can build display shelves, benches, window seats and other furniture into the walls of a cob house. This may translate to fewer bookshelves and other types of furniture purchases. Even major items like bed platforms and kitchen counters can be built into cob houses.
Cob House Durability
Around 50,000 cob buildings from the 18th and 19th centuries still stand in Great Britain -- a testament to their durability. In fact, you can find cob buildings from as far back as the 16th century in England. Climate is of little concern; even cold, damp air is no match for cob houses.
You don't have to be a professional or experienced builder to construct a cob house. Workshops and other educational materials can help with the details, and a plethora of cob house instructional videos are available online. Becky Bee, a pioneering leader in the cob house movement, compiled the Cob Builder's Handbook, accessible online free of charge.
Cob House Considerations
If you're building your own cob house, some financial planning is obviously in order. You'll save a lot in labor costs, but your time is worth money too. And cob house construction may not happen exactly on schedule.
Don't look at your cob house as an investment. Cob houses appeal to a much smaller segment of the population than a conventional house, so make sure you're diving in because you really want to live in a cob house -- for a long, long time.
House Alive: "Is Cob Cheap?"
Mother Earth News: "Grandpa's Hobbit House"