Author Archives: Mollie Curry

About Mollie Curry

Mollie got involved with natural building when she moved to Earthaven EcoVillage in 1996. She has taught natural building workshops, often at Earthaven and in the Western North Carolina area, since 1998. She has taught cob, plastering, straw bale, straw-clay, earthen paint, earthbag, and carpentry, as well as permaculture. Being involved in many of the natural building projects at Earthaven, as well as teaching and doing projects in other locations, has informed her building experience. Being an “earth” person, cob, plasters and earthen paints (alis) are her favorite things to work with.

What Makes a Wood Burning Stove a Rocket Stove?

The coziness of a “rocket mass heater” (aka “rocket stove”) is something we would love to have in our house. So when Lasse Holmes, esteemed natural builder and teacher of this DIY technology, said he was going to be in the area, we decided to sponsor him to teach a rare workshop here in Western North Carolina on the theory and building of the rocket mass heater.

Lasse is featured (among others) in Rocket Mass Heaters, a book by by Ianto Evans and Leslie Jackson. Leslie has cheerfully agreed to let us use a little excerpt with a link to the complete article explaining these wonderful wood-burning stoves at In fact, we are including a copy of Rocket Mass Heaters in the price of our upcoming Rocket Mass Heaters workshop (April 7, 8-9, 2016) since it is an essential resource for anyone serious about understanding and building one!

Excerpt from Rocket Mass Heaters by Ianto Evans and Leslie Jackson: What Makes a Wood Burning Stove a Rocket Stove?

The rocket stove burns cleanly and almost completely, and it does so by means of a combination of materials that is it built with, and geometry. The chimney is insulated, maximizing its interior temperature, thus helping the fuel burn completely. The wood is small, dry and straight. The chamber in which the wood burns is of a size to reflect back on itself, also maximizing the burn by helping it stay hot. The opening in the stove in which the fuel is fed, the chimney on which the cook pot sits and the gaps–around which the gases flow past and around the cookpot–are very carefully sized to control the amount of oxygen mixing with the burning fuel. The stove’s “L” shape or “J” shape contributes to an ideal mixing of the combustion gases for clean burning. It’s all about the proper conditions for complete combustion…
»Read complete article at

rocket mass heater diagram

What is Earthbag Building?

When the Mississippi floods, people use earthbags to hold back the water. And when you buy a sack of oats for your horses, it might come in a polypropylene bag—the same kind that they fill with sand or soil and use to direct the flood waters. But did you know you can build permanent structures with the same bags? In fact, you can get the material they make the bags from in a big roll—it is one long continuous tube at that point! This is before they cut it into smaller pieces and sew it to make bags—and that’s often even easier to use than the bags!

This building technique, which can use a wide variety of soil types, is called Earthbag Building. You can build foundations out of it, retaining walls, square houses, round houses, amoeboid houses, arches, vaults, domes, sculpture, benches, privacy “fences.” The list goes on!

Once you cover the sun-vulnerable woven polypropylene bags in either earthen, lime, or cement stucco, you have a very durable mass wall capable of carrying heavy loads such as cob, or adobe. And you can put the bags directly in contact with the ground, but you can’t do that with any earthen materials or straw and expect them to last. Thermally, earthbag acts a lot like adobe, cob, rammed earth, or earthships (tire houses), but is easier to build.

In the late 90’s, Steve built an earthbag house in the Bahamas with Carol Escott. They had heard about it at a natural building colloquium from Kaki Hunter and Doni Kiffmeyer, who had built an earthbag dome in Moab, Utah. So Steve and Carol asked them to come teach them their tricks and help them start it off—which they did! Eventually Kaki and Doni wrote a great book on the subject, and we highly recommend it! It is called Earthbag Building: the Tools, Tricks, and Techniques. Since then, Steve and Doni have also taught earthbag building in Jamaica.

Though we love straw bales for lots of functions such as houses, studios, wine rooms, etc. (they insulate so well!), they really don’t do well in contact with the ground. Since we moved to our place in Asheville, NC (which had absolutely no flat spot!), we have done a little grading and built some nice dry-stacked stone retaining walls, but we need more! So we have been thinking about and planning out some earthbag retaining walls. Earthbag is one of the few natural building techniques that can be in contact with the ground and not suffer.

We look forward to sharing our earthbag expertise with workshop participants on May 2-3, 2015 in a very affordably-priced two-day workshop called Earthbag Construction: Basics and Beyond. We are going to use mostly tubes. We will probably only use bags for the arch demo we are going to do.

Preparing for earthbags

Preparing for earthbags

Steve and four work exchangers (who are attending the workshop for free in return for help preparing the spot) did a ton of digging the other day, as you can see from the photos! This resulted in no less than four piles of soil in our yard. It is always astounding how soil “expands” when you dig it up! Some of these piles will get used to fill the tubes, but we will fill a good percentage of them with gravel. Also, we will fill the footing trench with gravel (and a drainage pipe).

Steve Kemble in trench dug for upcoming earthbag workshop

Steve Kemble, Natural Builder and Instructor

If you want to read a bit deeper into the earthbag method, check out this informative and fun article by Kaki and Doni—they are excellent writers. And good people too! And you can always subscribe to our Hug Some Mud newsletter to stay informed about our next straw bale, cob, earthen paint, lime and earthen plaster, or other workshops (just go to the Subscribe link at the top right on any page of Plus, we’ll be writing some more blog articles about natural building. Don’t worry, we won’t inundate you with too many emails!

More About the Instructors
One of the things Steve and I (Mollie) really love to do is pass on our knowledge, tips, techniques, and enthusiasm about natural building—straw bale, earthen paints and plasters, cob, earthbag, and more. We have been teaching for a long time (about 44 years worth between the two of us!), and doing natural building for a bit longer than that. We have learned a lot in those years, and taught a lot too—and still think we have a lot to learn. So we encourage our students/workshop participants to glean whatever is most helpful from us, and also to think for themselves and let us know how they think we could do it better. We love to see people excited and empowered by gaining the knowledge they need to make their own dreams come true in an environmentally conscious way.