EcoNest FAQ

How much will an EcoNest® cost to build?

An EcoNest® is an heirloom quality home built to last for centuries. A handcrafted home always costs more than a standard production home. Prices vary from region to region. The cost of an EcoNest® will be comparable to other high quality custom homes in your region. Good design can help you to plan a slightly smaller, more efficient home so that more money is available to spend on quality.

Is straw/clay wall construction suitable for every climate?

Because an EcoNest® has both mass storage and insulative properties, it is well suited for temperate climates that experience both hot summers and cold winters. The straw/clay walls must thoroughly dry before the application of finish materials such as plaster or wood siding. For 12″ thick walls we recommend that construction be timed so that there is a predictable three month dry season while the straw/clay is curing. The occasional rain during this time will not adversely affect the process. EcoNests have proven to be a durable solution for a range of diverse climates from Iowa and Wisconsin to New Mexico and Colorado. Straw/clay is not a good choice for areas without clay, and areas that do not have a dependable dry season.

Is there a builder in my area who knows how to build with straw/clay?

There may be. First, check out our Affiliates page to see if there is one in your area. Otherwise, e-mail us your name and location and we’ll let you know.

If you live within a 500-mile radius of our headquarters in Ashland, Oregon, and are a workshop graduate, you may be able to contract with the EcoNest® Company to have your timberframe and shell (walls) built in a workshop setting. In this case, we would work closely with your builder, who would need to complete an EcoNest® Intensive Training. Most builders will require technical support throughout the building process and we can help provide this support.

If you live more than 500 miles away from Ashland and decide to build an EcoNest®, then your next step is to find a quality custom builder in your area who is interested in learning the EcoNest® building system. We offer an training programs designed for experienced builders. There may already be an Certified EcoNest® Affiliate in your area. Contact us for recommendations.

Where is the vapor barrier in a straw/clay wall?

No vapor barrier is necessary in a 12″ thick straw/clay wall. Clay has the ability to hold many times its weight in moisture without deteriorating. It has the ability to wick water away from wood and straw and to release the moisture back into the air when the ambient air humidity drops. The clay itself acts as a huge network to intercept, hold and then release moisture in the first couple of inches of the wall so that no significant amount of moisture ever penetrates to dew point. Therefore a vapor barrier is not required and in fact would be detrimental to the wall because it would trap moisture setting up conditions for decay.

Will clay/straw be approved by our building department?

Straw/clay has already been approved in many building departments through out the world. Building codes in the US have a provision for alternative methods and building materials. It is left up to the discretion of the building official as to whether or not you will be granted a permit. Straw/clay is a relatively new building system in this country and your building department may be unfamiliar with it. The official NM guidelines may be a helpful document when presenting your case to your local official. Be knowledgeable, be prepared listen to your official?s concerns and be respectful.

Can we get a mortgage for this building system?

Several of the EcoNests that we have built carry conventional mortgages. Because most lenders are familiar with timberframe structures and the straw/clay is non-load bearing, there is usually not a problem. However we urge you to speak with your lender early on in the planning stages.

What about mold?

All straw contains mold as does any other plant material. Mold also rapidly appears on any industrialized building product with cellulose in it. Gypsum board, also known as wallboard or drywall, the most common interior wall surface in standard construction, contains cellulose in the form of recycled newsprint. All wood is composed of cellulose as well. If exposed to certain conditions they will become moldy within a few hours. This is because they provide food for ever present airborne mold to colonize on. When the clay/straw mixture is wet dormant mold spores will become activated. We add Borax to the water to retard this process however there may be some mold present on the drying surfaces. This is normal. Once the walls are dried and plastered air quality tests have shown that there are no elevated indoor mold counts. In fact the mold counts are lower than those found outdoors which is what one would expect to find in a healthy house. Occasional wetting of the plaster will not cause mold growth because of the exceptional ability of clay to wick water away from the straw and re-release it into the air. This is why, throughout history mankind has successfully used clay as a natural preservative. The key to a mold free home whether it be of clay/straw or standard construction is to have good construction which prevents water intrusion, good ventilation which prevents the build-up of humidity created by human activity and good maintenance so that any water leakage is detected and repaired before it becomes problematic.

Is it important to attend a workshop?

Until very recent history natural homes were the only type of homes available. However if you are considering building a natural home today you are an ecological pioneer and you will find yourself becoming a spokesperson for the burgeoning natural building movement by your example. This is not for everyone and we feel strongly that it is important to be well educated and articulate about your choices. There are several different systems for building with natural materials and you may wish to attend a variety of workshops including straw-bale, cob and adobe before deciding which system makes the most sense for you. The workshop provides a fertile meeting ground for like-minded people from across the continent. There is often an opportunity to experience finished homes and meet and interview people who have already been through the process. It is also a time to learn by doing and to see if these materials speak to you loud enough for you to be able to speak for them, because if you build this way people will come.

Can I be an owner-builder and save money?

Yes. You can save money by being an owner builder provided you have time, patience, building experience or a willingness to learn. Most people who are gainfully employed in their own field do not find it cost effective to quit their jobs and learn the building trade from the ground up. However, people do not always become owner-builders for financial gain. Some of our customers have done so in order to fulfill a lifelong dream of participating in the hands on process of creation of their own home.

Will you build an EcoNest® out of state?

The EcoNest® Company will contract for a timber-frame and demonstration workshop of straw-clay construction for Owner-Builders or Contractors who have already graduated from an EcoNest® Workshop.

Can we save money by doing our own drawings?

The integration of a timberframe within a design is an art. These buildings will stand for centuries and we feel that the initial investment in professional design is essential. The EcoNest® Building Company has an experienced design team that will work with you to create the ideal design for your new home.

Are there apprenticeship opportunities beyond the workshop?

The EcoNest® building company has an ongoing training program for aspiring interns. The interview process begins when the potential intern attends a workshop and qualified applicants are accepted as space and scheduling permit. Within the EcoNest® Building Company an apprentice will be working with skilled craftsmen who have a wealth of knowledge to share about design, timber-framing and ecologically sound building.

How is light clay/straw construction different than straw bale?

Straw bale and clay/straw construction are actually quite different in many ways. Clay/straw construction combines loose straw with clay soils and water to form a 12″ thick monolithic wall that contains both the insulating properties of straw and the mass storage capacity of earth. In the mixing process each straw fiber is coated with clay making it fireproof, vermin proof and resistant to decay. The clay/straw walls have sufficient texture to receive natural plasters directly without the need for additional netting. Due to the high clay content clay/straw walls are hygroscopic which means that they have the ability to moderate and balance indoor humidity, an important health promoting factor.

How much wood is used in an Econest® compared to a stick-framed house?

When clay /straw walls are load-bearing with 2X4 Larsen trusses on 24” centers, approximately the same amount of framing lumber is used as a stick frame house. However, none of the exterior plywood sheathing is required. In addition, keep in mind the expected longevity of an EcoNest® to be 200 years serving 4-6 generations.

When a timberframe is utilized and the perimeter walls are not load-bearing requiring no double top plate or exterior plywood sheathing, the overall amount of wood is 20% less than a standard frame house.

Have you had any experience or success with foundations not made of concrete?

In Iowa, during the 90’s we used rubble trenches successfully on several EcoNests®. This summer we will be doing our first rubble trench on an EcoNest® in New Mexico to move towards our goal of eliminating Portland cement from our homes. The production of Portland cement is an energy-intensive process that is responsible for 6-10% of global warming depending on which study you read.

Besides adding a few years to your life, what is involved in hosting an EcoNest® build?

To host an EcoNest® workshop, you first complete our builder training. Secondly, your home must be an EcoNest® design – stock or custom plan that is properly designed for clay/straw. You can either contract the Econest® Building Company to supply and install the timberframe and clay/straw or you can contract EBC to lead a training.

Does shrinkage become an issue and how is it addressed?

Shrinkage occurs as the walls dry out and settle over time. Two things influence this ? evaporation and weight. As the wet wall mixture dries, it shrinks minimally. The weight of the wall however is significant, and can be 400 pounds per lineal foot for an 8′ wet wall. By installing stabilizing bars every two feet, the wall is effectively “hung up” in two-foot lifts which reduces the weight, resulting in 80% less settlement. Shrinkage gaps as well as voids are chinked with a heavy mixture of clay/straw.

What is the cost of clay/straw compared to conventional construction? Are there sq.ft. or wall volume costs you can share? Again, this is with an eye to promoting clay/straw to potential clients.

Clay/straw walls cost approx. $15/sf when contracted. This price is for building sites with good access to all walls. If access is limited, there is an additional cost for setting up a delivery system to supply all walls with clay/straw.

I’d like some pointers on differentiating and promoting the benefits of clay/straw from straw bale when speaking to potential clients.

Straw bale’s biggest advantage over clay/straw is that it is a dry technique and can be built even when the temperatures dip below freezing. Clay/straw cannot and requires more carpentry skills than stacking bales. Straw bales are more vulnerable to vermin and weather than clay coated straw. Having said all that, both are excellent techniques and one should build with the system that they resonate with.

What type of doors do you recommend for outside doors, taking into consideration weathering and low maintenance?

I recommend a beautiful, durable door for your entrance.

Can you talk about living roofs, experience, lifetime, strength issues (framing, etc.)?

I don’t know about building living roofs. Please visit www.ranacreek.com or contact Paul Kephart, at paul@ranacreek.com. Paul currently directs the Living Architecture component of the soon-to-open, 2-acre living roof atop the California Academy of Sciences building in San Francisco’s Golden Gate Park. Designed by the Renzo Piano Building Workshop, it is considered to be one of the world?s most challenging “green roof projects”.

Have you ever renovated houses, removed conventional walls and put in clay/straw? I would like to someday remove my ground floor stick framing (rotten/ant ridden) and put in a post and beam/clay/straw combo.

Clay/woodchip walls with lath work best for interior walls as they do not require any stomping and the necessary clearances above the wall to facilitate this “ramming” process.

Can I send you my plans for the cottage and have you give it the “Econest®” look over? Would you do this for clients wanting to build this way or does there have to be a workshop attached?

Workshop participants can have their plans reviewed at the workshop. Others can have their plans reviewed for a fee.

Can you briefly cover earthen floors and your preferred methods?

Earthen floors and plasters are more involved than one might imagine and are best introduced in a hands-on workshop. Both can be a life-long vocation.

Will you tell us how many square feet of walls we filled and how many bales/cu. yards of soil and clay we used?

The average 1500 sf house will require approximately 125 bales and 20-30 yards of soil. Conditions and amounts may vary.