Maya Creek Ecovillage

The Shelter Plan

There are currently no livable shelters on the land, so everything will be built from scratch. We will be using the most current methods in natural building in our construction. Based on the availability of building materials as well as the climate we will likely be utilizing hybrid straw bale and cob, however members may build any kind of structure as long as it is designed to be as environmentally conscious as possible and is approved by the group. We definitely encourage any kind of building material that has a low embodied energy or is reclaimed.

Straw Bale Construction

Straw is the left over part of grain crops when the edible grains have been removed. In the late 1800's when mechanized straw balers came on the scene, it didn't take long for pioneers to turn to the bales as a building material. The durability of straw bale construction is evidenced by the existence of many of those original buildings today. As long as a straw bale building is protected from moisture it will last an idefinite period of time.

The case for straw bale constructions is convincing. It is in an excellent insulative material and the R value of a straw bale wall ranges from the 30-58. Compare that with a stick framed and fiberglass insulated wall with an average R value of only 16.

Straw is also considered a waste product and every year millions of tons of straw are burned releasing thousands of tons of carbon monoxide into the atmosphere. It is estimated that burning rice straw in Oregon alone releases more than double the carbon monoxide of all the power plants in California.

Not only would using that straw for construction reduce greenhouse gas emissions, but it has been observed that if all the straw after the U.S. grain harvest were collected and used in construction it would build over 5 million 2,000 square foot homes. Straw also has an incredibly low embodied energy, especially if locally grown. Concrete uses about 5,800,000 BTUs of energy to create 1 ton. To create 1 ton of straw only requires 112,500 BTUs.

Cob Construction

Cob has nothing to do with corn cobs. It is a mixture of sand, straw, and clay that is sculpted in place to create the walls of a structure. These are the same basic components that are used to make adobe, but instead of making bricks and stacking them in a traditional way, a cob wall is a one solid unit, a monolithic structure. This monolithic technique gives the walls incredible strength as long as they remain dry. As with straw bale, water is the number one enemy, that's why excellent drainage, stem walls, and big roof overhangs are standard on these types of buildings.

Humans having been building with cob for thousands of years. We know for certain that cob was used in northern Africa during the 11^th century. There are cob homes in England that are still inhabitted after more than 500 years. Cob is currently experiencing a revival and is especially popular in the Pacific Northwest.

Cob has excellent thermal mass and can regulate the swings in temperature between day and night. It keeps the house cool during the day but slowly absorbs the suns heat and releases it throughout the night. It also allows for almost any shape imaginable.

Hybrid Buildings

It is very likely that we will use a combination of both straw bale and cob in our first buildings. Members will be able to decide for themselves how the want to build. We will use the two materials where their benefits can be be utilized. The eastern and south facing walls will be made of cob to absorb the sun's energy and the west and north facing walls will be straw bale to provide insulation in the areas it is needed most.