Miscellaneous Questions about Strawbale Buildings

Catherine Wanek After growing up in Las Cruces, NM, Catherine lived in various places until she settled in Los Angeles to work as an assistant director in Hollywood film production.  Lured by the beauty of New Mexico, Catherine purchased the Black Range Lodge in the 1980s with a vision of making movies there, and developing the property into a lush permaculture landscape, which now includes an abundance of fruit trees.   Since then she has been providing a comfortable respite for others seeking rest and relaxation in a natural, healing environment.  After building a straw-bale greenhouse in 1992, she became an advocate of “natural building”, traveling internationally to research and educate, authoring books and videos, and hosting hands-on workshops at the Lodge to spread the word about ecological construction methods.  Books she has authored on these subjects include The Hybrid House: Designing with Sun Wind Water and Earth, The Art of Natural Building, and The New Strawbale Home.

Questions and Answers

Q: I work for a natural construction company, building mostly load bearing straw bale homes. I have also done adobe floors and interior and exterior plasters. I will be in california and am interested in seeing some of the straw bales being built there. Do you know of specific areas where natural building is prominent or have any contacts for me?

A: (Owen Geiger) For contacts in California I recommend contacting builders, architects and engineers who are members of CASBA (California Straw Building Association). In many ways, CASBA is a world leader in testing, design and building. Please consult their Resource List of members.

Q: My husband and I want to build a strawbale house, but because of how late it is in the year, we've been debating between going for it (and being very rushed--Northern Michigan have very wet autumns) and putting in a trailer until next spring. It would be a cheap, old one, since we want to save money for the place we'd "really" be living. As I was going to sleep last night, I was thinking maybe it wouldn't be too bad--I could at least decorate it and do anything I wanted to it, even though the old ones are poorly insulated. Then, half-awake, this occurred to me. Why can't I strawbale a trailer? Has anyone done this?! I'm thinking basically just getting an extra large slab and using the trailer as the "frame". Many of the trailers around here have "hats" (sloping roofs) on them for snow and insulation. I was thinking then next year, I could expand and put on a larger living room, make the trailer's living room a dining room. And for that matter, trailer roofs are weight-bearing--the snow around here proves that--so I could even put in an upper story... What do you think? Would this work? I'm thinking of totally encasing the bales, including from the underside of the trailer, though of course, I'll have to leave a crawlspace entrance. Please give me your opinion, because my husband just thinks it's finally driven me crazy.

A: (Owen Geiger) Yes, this has been done. There's a drawing in Build it With Bales, Version II, page 24. Also, this book is the best how-to SB guide for
owner-builders. Other books get bogged down in history and other topics.) The first step is to check on local building regulations to see if this is allowed.

Here's the basic process:
1. Build part of the house (one room, for example) and park the trailer inside. (Think "carport.") A post and beam structure is recommend for climates with heavy snow load and building codes. This lets you get the roof up quickly and then add the walls, etc. later. You could definitely do this before winter if you build small.
2. Build the rest of the house as you can afford it.
3. Sell the trailer to someone who wants to do what you just finished doing!

There's no need for a slab floor or a crawl space. I recommend building a post and beam structure on pier footings with "Sono tube" cardboard forms. Later, add a rubble trench foundation and grade beam to support the walls. You could also used tires filled with rammed soil, etc. This same book has lots of drawings of low-tech foundations. But again, check on local building regulations.

I highly recommend earthen floors. An article I'm writing for The Last Straw Journal explains how wood framed floors with synthetic carpet use 1,618 times more energy than earthen floors. And, earthen floors last for centuries if done properly. There's a free article on my using tamped earth: http://www.grisb.org/publications/index.htm Do not use bales as floor insulation. They will eventually rot. Also, be sure to insulate the foundation and floor with rigid foam in cold climates.

Q: I think you misunderstood what I was asking. I'm considering incorporating the trailer into the building, as in a permanent part. Just burying it within the strawbales, as the core of the house. Would there be any reason why I couldn't "wrap" a trailer in strawbales?

A:(Owen Geiger) Yes, this could be done. It's called a bale wrap retrofit. The windows would be somewhat difficult to detail, but it could be done. Removing the trailer at a later date makes the most sense to me. What will you do when the trailer deteriorates? They're often poorly built and full of manmade materials that off-gas VOCs (plastics, synthetic carpet, particle board, etc.) And, you will never attain the interior aesthetics that come with building a straw bale house. I would guess the resale value would be considerably less, as well. The drawbacks outweigh the advantages in my opinion. Consider living in the trailer next to the house and avoid all these issues.

C: I'm faced with a building inspector who had never HEARD of strawbale construction and started shaking his head when I (stupidly) used the words "alternative building material". Trailers are fine because they come pre-wired and all and he has little say on them. Building on to an existing trailer is also okay, and most people up here have entrance/wind blocks and roofs supported by poles... Some of the trailers around here don't resemble trailers at all, because they've been incased in add-ons. Especially, the older and shorter ones. One not far from our building site is a 1960, 58 foot trailer that looks like a cottage because the back side is entirely additions and the other three sides are wrapped in screen porch. I probably won't do it. It was just a thought. Thanks for answering.

Q: I'm form Estonia and I'm learning environmental technology at the University of Tartu, and my specific study area is ecological building. I graduated this spring. So I'm very interested in green building. When in Estonia the green building stuff is very primitive, I want to practice this outside my country. So, I want to ask you: Do you know some places in USA where can I practice my knowledge about green building and technologies, it doesn't have to be a school (my english is not sufficient to learn this in some university) but do you know some volunteer programs or something like that where I can practice my english and concurrently be doing and learning this ecological building stuff?

A:(Owen Geiger) Yes, there are a few areas in the US where natural building is growing quite rapidly and you could receive on the job training. One good source is the Fall Resource issue of The Last Straw Journal: They list companies, resources, architects, websites, etc. by state and country. Do some research and you will see that California, Colorado, Arizona, and to some extent New Mexico, are leading the natural building movement in the US. Oregon, Washington, and a few other states are quite active. Be careful -- southern states like New Mexico are much poorer than states like Colorado and California. I recommend searching for jobs or work/trade opportunities in these states and gain hands-on experience. Universities are good up to a point, but actual experience is important. Work/trade (internship) opportunities could be ideal for you. Typically meals are provided in trade for work and training. Some of these are good, some bad.

Also, try to attend some conferences and workshops if possible. Some are expensive, some not. The recent Colorado straw bale conference was only $40, yet it attracted top experts. Almost all of these conferences are posted on The Last Straw Journal website and GreenHomeBuilding.com. One approach is to volunteer your services at workshops: offer to go early and help them, and they may let you attend the workshop for free. (This will work best if you are in the US.) And read everything you can from libraries, websites, etc. Keep learning all the time and you will be successful.

Q: I'm considering construction of a hybrid home that would include an attached greenhouse/sunspace. How would you go about attaching this type of structure to straw bale construction and how would you approach a building consisting of straw bale that is partially earth-bermed? What kind of foundation is usually used for straw bale and if concrete and masonry, how would you prevent the masonry from wicking moisture into the bales without using plastics or treated lumber? I imagine I can find some of this information in a book-what would your top recommendation be for someone with a fairly extensive construction/architectural background?

A: (Jeff Ruppert) Without going into great detail with regard to the actual connection of a greenhouse to a SB building, I would seal the plaster somehow to minimize any vapor intrusion. Try to place some sort of ledger into the bale wall to attach the structure and seal it well with caulk and flashing. I would stay away form berming anything against bale walls, and stick to concrete, Rastra or tires filled with earth to act as retaining walls. Concrete is very common due to it’s durability and predictable strength. You can use cedar, redwood or plastic lumber in-place of treated lumber. You can use black tar in pace of plastic, but from the nature of your questions I would guess this won’t be a good alternative for you. This is a tough question. I don’t have an alternative for plastic. Most books, in my opinion, are not technical enough. However, I like Serious Straw Bale and Build It With Bales, Version 2. Good luck.

Q: At least one strawbale book talks about retrofitting a strawbale 'veneer' onto a poorly insulated structure. What sort of pitfalls are involved in this approach? I imagine the roof overhangs would typically have to be extended to shelter the strawbale walls. Would it be a good idea to migrate the windows to the outside of the new strawbale exterior?

A: (Jeff Ruppert) One of the main pitfalls associated with retrofits is the foundation. If you are in an area with frost heave, you will need to put down support for the bales to frost depth. The other alternative is to sink piers along the wall length and span with a grade beam which incorporates a void form for soil expansion during frost events. If you do not have frost heave issues, it is a fine approach to rehab. The windows work best when on the exterior not only in a retrofit. Good luck!

Q: How much would it cost to build a 1800 sq ft strawbale home? Additionally, I am considering buying plans from eplans.com, and was curious if there is that available for eco homes?

A: (Kelly) The cost of building a straw bale home varies considerably, depending on the design, whether it is owner-built, materials choices, etc. It is not unusual for strawbale homes to actually cost a bit more than conventional stick-built homes, because of all the custom work that often goes into them.

As for buying stock plans via the internet, there are quite a few companies providing these, but very few of them will offer plans for strawbale houses. I have just started listing home plans at my sister site, www.dreamgreenhomes.com , but I don't have any strawbale plans up yet.

Q: What is the coefficient of thermal conductivity of strawbale wall?

A: (Jeff Ruppert) The R-Value of a bale wall assembly is approximately R-30. This is the resistivity number. The inverse would be the conductivity or 1/30 = 0.0333.

Q: How many stories tall can you build a straw bale house? ie Can you build a castle?

A: (Jeff Ruppert) Generally speaking, you can do whatever you want. As with everything else, there are practical limitations though. It will depend on where you want to build. For example, if you are in a seismic area, it will be difficult to build tall structures due to the fact that bale construction is heavy. This is a detriment in earthquake zones. Other than that, you can do anything with a frame involved in the design.

Q: I live and work in northern Scotland (Inverness) and would like to build my own house. I have looked at strawbale but don't feel right. It is cold 50% of the year and if you can't see any hills its raining. I like the idea of straw but will it work??? p.s. I am planning to "self build" without much building time which attracted me to this kind of building. PLEASE HELP or offer an alternative.

A: (Jeff Ruppert) Yes, you can build a bale house in Scotland, but you will need to apply all of the principles of keeping things dry to the maximum! Scotland has a history of making buildings low in the earth covered with thick thatch roofs to shed rain. The walls were actually mounds of earth. Things like LARGE overhangs and detailing windows correctly will be vital!

Q: My boyfriend and I have been thinking of building a straw bale home. Could you give me an idea of the cost. We live in northern VT and hope to find an option that we can afford. We are looking at maybe a 2 bedroom.

A: (Jeff Ruppert) A rule of thumb is that your house, whether the walls are made of bales or not, will cost the going rate of new homes in your area. Walls only account for roughly 15% of the cost of the project, so the overall cost will be in-line with other custom homes. You will pay for the same footprint, but end up with a little less interior space, due to the wall thickness. So, your usable square footage will cost a little more - on the order of 7% or so.

Q: My partner and I have been blessed with the opportunity to build our own home. We are both very interested in straw bale architecture, but realize that it is the more challenging route to take (as opposed to the well-laid-out conventional building route). We live in Corvallis, Oregon, where straw bale is allowed in the code. However, to date, there is only one other straw bale home that has been built in the county. My first question is: How do we locate an architect (preferably in the area) who has experience in straw bale architecture? Second: How do we locate a builder/consultant to help with the actual raising/plastering of the walls?

A: (Jeff Ruppert) I would suggest looking at The Last Straw resource edition. The Last Straw is the quarterly journal on bale construction and they have an annual resource issue that is separate. When choosing builders and designers, check their references! Both should be reputable and not fly-by-night people. There are many self-made builders who literally only know how to stack bales. Use common sense! Good luck.

Q: I am considering the purchase of 40 acres west of Pueblo,co. And would like a to build a straw bale home. The property I am interested in has a 3-5 year old MODULAR HOME. Is there a way to retro fit the existing structure to a straw bale home? My intent would also be to add on to the home using straw bale building methods.

A: (Kelly) Yes it is possible to retrofit a home as you suggest, with some significant alterations. The strawbales (generally placed on the outside in this scenario) need their own substantial foundation, and then the roof structure needs so be extended to cover them. Adding additions to this could be done with conventional strawbale building techniques.

Q: We have been wanting to build a strawbale house for some time. We moved onto some land and are living in a single-wide trailer right now. We plan to have a slab poured for the floor, but we will do everything else. We would like it to be appx. 2000 sq. ft. with 4 bedrooms, just a basic rectangular clerestory home. Would you be able to give us a price estimate based on this information? We would like to spend as little money as possible. We've already got water, sewer, solar-electric, and a propane tank. We were wondering if maybe we could build half the house, then move into it, pull the trailer out, and build the second half where the trailer is. Or would it be better to just build the whole thing at the same time?

A:(Owen Geiger) The cost of strawbale houses usually turn out to be the same as conventional houses, because the bale walls are just one part of the house. You still need a foundation, plumbing, electrical, roof, kitchen, etc. You can get a quick and fairly accurate cost estimate by calling a few builders and asking for the going per square foot price for a generic stick frame house.

That said, there are many many ways to cut costs, and this has been my focus for the last 10 years or so.

Building codes greatly restrict what can be done, however. You'll need to investigate what is and isn't allowed in your building jurisdiction. Besides talking with local building officials, one option is to locate builders and architects in your area who are using strawbale, earthen construction, etc. and try to glean as much as you can. The Fall Resource issue of The Last Straw lists resources by state and country.

You can build around a trailer and/or build 1/2 of the house first, but you'll likely need to have your plans approved by building officials. If local building officials are not receptive, you may be able to live in the trailer next to the house during construction. Another option is to plan very carefully for future expansion and add the second 1/2 later. With a simple
clerestory house this shouldn't be too difficult.

Q: I live in Serbia and plan to build a load bearing 120 square meters strawbale house, 1 story + penthouse. Is it OK to make a penthouse on a load bearing wall? I want to apply lime+sand+water plaster directly to the strawbales. Is this good or do you have some other kind of plaster in mind? What suggestions do you have for floor insulation? My uncle in Denmark is using sea shells, but I can't. Some other way including straw perhaps?

A:(Owen Geiger) Good to hear of a strawbale house in Serbia! Yes, two-story strawbale houses are acceptable. The main thing is to use very dense bales. There isn't space here to define all the specifics, so do your research on this. The Last Straw is one of the best sources. All of the leading books on strawbale address this point. In general, livestock bales would not suffice (unless you are very fortunate). You'll need high quality "building bales." Otherwise, the bales will likely settle and crack the plaster.

C: As for the ''building bales'' it will be tricky. Here, people make the bales the same way, and as far as I know they are all the same size- 1m length, 50cm depth, 40cm height. The only thing I can do is to check them for myself and maybe take someone (I can trust) who has experience with straw bales to give me advice. I hope I'll have the opportunity to choose the bales I want. I already saw some people have nice yellow straw bales, and other have darker ones.

Farmers can adjust their baling machinery to increase the compactness of the bales. Look around, ask questions, inform farmers of the potential of strawbale building, and show them some nice pictures. Farmers in the US who have made the extra effort are making good money on a "waste" product. The yellow bales are the ones you want. Dark bales are deteriorating.

Also, try to reduce the weight of the upper story. I would advise against tile roofs, for example. And, pre-compress the bales with tie-downs and allow ample time for settling. In other words, don't plaster until the entire building is finished and the bales are done settling.

Lime plaster is good choice. Maybe you could contact some local plasterers to be sure you get the mix just right. You may want to add some stucco mesh around door and window openings to reduce cracking.

Floor insulation: Porous volcanic rock (scoria, pumice, lava rock) is a good choice. It has lots of air spaces and doesn't rot. Using straw below grade is not recommended, because eventually it will rot.

Proper foundation design requires specific information on soil bearing capacity, soil expansion, frost depth, seismic conditions, etc., so my advice is to consult with a foundation engineer in your area. General foundation advice: Yes, you can use a "regular" foundation (steel reinforced concrete). There is no need to build a thick foundation the same size as the bales. Build a conventional-sized foundation, add your floor frame and toe-up, and stack the bales on top of this. Rubble trench info: I'm a little confused about what you are referring to by "rubble infill in the middle." Do you mean rubble or gravel under the floor?

Q: We live in a 1930 small ranch style house outside of Sacramento, CA. In the 50's there were 2 small additions. Now we are preparing to add on again, and would like to do so with straw bale construction. Is it significantly more difficult to attach strawbale construction to an existing older home? Would you recommend it? Originally we thought we would rebuild the house on this 4 acre property, but we have decided it would be better to work with what we have, but I'd like to use more energy efficient green building type construction methods.

A:(Owen Geiger) Straw-bale construction is well suited to both new construction and remodeling. As is true with any construction project, including adding additions, the need for careful planning cannot be over emphasized. It is quite challenging to get various living spaces that have been built over the years to flow together seamlessly, and get all the roof lines, etc. to join

There is nothing difficult about attaching a strawbale addition to a wood-framed house. One technique uses expanded metal lath (the kind plasters use). Cut pieces of lath for each row of bales (say 12"x12"). Use landscape pins or u-shaped pins made of 12 gauge galvanized wire to fasten the lath to the bales, and use screws to secure it to the wood structure.

Standard strawbale building techniques apply to strawbale additions: provide an adequate roof overhang, detail window and door openings correctly to prevent moisture damage, allow vapor to pass through the wall, etc. Wood siding can be applied over the bales so the addition matches the rest of the house. A knowledgeable strawbale designer/builder will be
able to guide you through this process.

Q: Can you help us find 500 straw bales that can be delivered quickly to our dog rescue site near Payson, AZ? The weather is freezing and we have 39 dogs left that are more difficult to find homes for so we may have to shelter them over the winter.

A:(Owen Geiger) Check your local feed stores.  Bales are widely available all over the US.  Low quality bales for livestock will be sufficient.  You might even find a farmer who's willing to donate them.

Q: We are planning on building a straw bale tipi. Our questions come from the exterior finish. The structure will be 40 feet at the base and up to a 40 foot peak. From the bottom to appr. 15 ft up will be a wrap around porch. We have looked at stucco and metal for the most exposed part of the structure. What do you think would be the best application with minimal up keep? And if the best is Stucco do you know of a good waterproof, breathable stucco?

A:(Owen Geiger) The main rule of thumb with strawbale is the need for a protective roof overhang.  Exposed bale walls (such as the tipi you describe) will not withstand the weather. Options: Use bales to line the inside of the tipi.  You will lose lots of space, but the bales will be protected.  Another option is to use bales up to the level of the wrap around porch, and complete the top of the tipi with another material such as wood (lumber or poles) or bent saplings.  You could also incorporate a skylight and smoke hole into the peak. Best choice I can think of: Line the outside of the tipi with bales up to the height of the porch cover.  This gives you extra space inside the tipi.  Then finish off the top of the tipi however you like.

Q: I am thinking of building a straw bale house in the shape of a trapezoid with the largest side facing south. It is to be of a load bearing design with a shed roof. What I would like to create is a roof starting at 1 story height at the back and 1 1/2 story in the front creating space for extra room. My question is: How do I pre-compress the side walls when they are on an angle and is such construction possible to do with a load bearing set up?

A:(Owen Geiger) Here's some general advice: - load bearing SB is only suitable for small, simple buildings - you face the risk of differential settling: load bearing walls settling more than the side walls, which can lead to cracking plaster, etc. - post and beam has many benefits and doesn't cost much extra - side walls are compressed the same as other walls.

Q: I want to build a second story bedroom/study (about 16'X 20') on an old adobe I'm remodeling (flat roof). For reasons of (less) weight and work, I'd like to do it with straw bales or 2X6 wood frame, although frame would be more difficult to apply a natural lime plaster, I suspect. Can you tell me how much less the straw bale structure would weigh compared to adobe, when all is said and done, and if my idea is feasible on top of a constructed wooden bond beam? (My adobe walls below are and/or will be 14" or more thick.)

A:(Owen Geiger) The weight of the second story is probably not a major issue, assuming the foundation, lintels and/or bond beam are structurally sound.  Adobes can carry massive loads in compression. Other factors are more important: climate and the importance of highly insulated walls (ex: very hot or cold climates are points in favor of using strawbale), importance of having a quiet space (strawbale structures are very quiet), aesthetics, and usable floor space.  You will lose some floor space with thick bale walls.

Q: Are there some extremely detailed books or movies that you would recommend for someone who wants to build their entire house on their own? I need to know how to handle electrical and plumbing needs of the house as well. Do you have any contacts that are in Southern California? This is actually where I want to build this house. Are these houses pretty simple to build?  Also are there any blueprints or plans that I can get that I could go by or do I need to create my own plans?

A:(Owen Geiger) Get the Fall Resource issue of The Last Straw.  It lists resources by state and country.  You can locate designers, find stock plans, etc. California is a major hotbed for strawbale.  The California Straw Bale Association has a list of members, etc. Simple to build?  Yes and no, depending on your skill level.  Building a SB house is about the same as building any other type of house: you still have a foundation, plumbing, electrical, roof, etc.  The cost and length of construction is pretty much the same as conventional building as well.

Q: My family and I are interested in straw bale Housing. Q: Can you put straw bales in a existing house? Q: Can a person build dome home using straw bales? My family and I live in South Dakota. Q: Can you use straw bales to build a basement?

A:(Owen Geiger) Q1: Yes, you can retrofit an existing house.  Just be aware you will lose a lot of floor space, and you will need to work out the door and window details, electrical, etc. Q2: Domes are not recommended.  Any rain or snow will quickly rot the bales.  Moisture is the #1 enemy of straw.  A good roof is critical to protecting the bales. Q3: This is not recommended because the bales are vulnerable to moisture damage.

Q: After reading many wonderful entries, I came across a submitter to the Q&A forum who mentioned building a house with an interior courtyard. This sounds tranquil and a design that would fit my needs perfectly. However --> would it be possible to build one section of the strawbale house at a time? and add on as finances allow? It seems as though strawbale housing is perfect for this kind of pocket savvy adventure. Do you suggest any reading on the subject?

A:(Owen Geiger) This design does have a number of desirable qualities, as you've mentioned.  It's a great way to add extended living space, while keeping your privacy. There are some drawbacks, however.  For instance, costs could be higher than more compact designs, due to the additional walls.  Another consideration is traffic flow through the house.  A good designer/architect can work this out.  Also, be sure to allow for adequate drainage away from the courtyard.  In a rainy climate, this could be a serious issue.  In any case, I would add wide roof overhangs to keep moisture well away from the bale walls.  This has the added benefit of creating sheltered space within the courtyard.

Yes, you could build it incrementally.  It would be best to work out the entire design in advance to reduce problems. I am not aware of any books or resources devoted to this design.  I've seen pictures here and there, and they've been beautiful!  One related idea that might be of help is a book on Santa Fe hidden courtyards.  Amazon must have it.

Q: I am investigating building a straw home in Northern Iowa. The property has a 100 year old home on it that I would like to utilize. I understand the foundation issues and extending the overhang. What I'm wondering is, if I remove the exterior to upgrade the wiring and plumbing, can I leave the existing interior lath and plaster in place and just place the bales tightly up against this or would I need to remove the old plaster or take other protective steps to bridge the materials.

A:(Owen Geiger) There's very little experience to draw from on this, but I'd say your plan is okay.  Leave the plaster in place, which will act as a fire break. Also, follow good building practice throughout: raise the bales well above grade, drifting snow and the splash zone.  Caulk and seal all paths of moisture and humidity into the wall, especially around doors, windows, outlets and other wall penetrations.  Use wide overhangs at least 24"-36".  Add a moisture barrier on top of the bale wall to guard against roof leaks entering the bales.

Q: My husband and I have been discussing the idea of building a straw bale home on property we own in Fallbrook, Ca. and have not found any specific references to SB houses and basements. Do you have any references or information on this idea?

A:(Owen Geiger) Basements are certainly an option as long as you keep the bales above grade.  For example, if you use a wood floor frame and concrete foundation, you can build it like a conventional home.  I recommend a wood toe-up to raise the bales off the floor.

Q: I built a modified post and beam will bale infill in Laramie, Wyoming. Great house, I will never live in an other type of house. I tried several ways to buy insurance for the construction phase, and have tried several more times to get homeowners insurance, all to no avail. In looking through the different web sites, I see a lot of grousing about trying to convince local building inspectors to approve plans for strawbale buildings, but I never really found a good place that mentioned that they were successful in finding homeowners insurance for any kind of strawbale house. Can you help?

A:(Owen Geiger) Insurance companies have made it more difficult to obtain insurance since the recent hurricanes.  (They lost billions.)

Q: Can you give me names of builders in Western North Carolina that build strawbale homes? Is this something an owner can help with or do they blow the strawbale in and how can I find out more about this
safe strawbale construction?

A:(Owen Geiger) Please order the Fall Resource issue of The Last Straw Journal to locate builders, architects, and any other local resource state-by-state.

Never heard of "blown in strawbale."  Please clarify.

Safety: In general, follow standard building safety precautions.  Construction is dangerous and builders are strongly advised to learn safe techniques.  The biggest risk involves ladders and working in high places, and power tools.  Be careful!  That said, strawbale building is no more dangerous than conventional construction.

Q and A (Kelly):

1. Are these buildings becoming more allowable by building codes?

Several states, including Arizona and New Mexico, actually have codes drafted specifically for straw bale building; in areas where this has not occurred, these buildings can be permitted through certification by engineers.

2. How long do straw bale buildings typically last?

Some of the original straw bale buildings built in Nebraska over a century ago are still standing. The more recent straw bale building boom has been over the last 15 years, and those that were carefully built to avoid moisture problems show no sign of exteriorization.

3. Can straw bale walls bear significant loads?

There are many load-bearing straw bale buildings, but these rarely go over one or two stories high. Often the bales are pre-compressed before a roof load is applied, so  that they show little or no compression later.

4. What special arrangements have to be made for wiring, chimneys, etc.?

Wiring can be either placed in conduit, or if recessed sufficiently, it can be plastered over. Chimneys obviously need to observe all cautions regarding proper spacing and insulation relative to combustible materials.

5. Are any statistics kept on the number of such buildings going up these days?

There are several straw bale associations that might keep some data on this, but I am not aware of it. In one small community in Colorado of about about 1,000 population, there must be over 50 straw bale houses!

Q: I live in New Brunswick Canada.My house is an old wooden farmhouse, very poorly insulated. This year I have decided to use straw bales around the exterior foundation of the house to cut the wind chill. In the spring I will remove the bales for compost. My question: should I put plastic between the strawbales and the house?

A:(Owen Geiger) For one, there's no need to.  It's just a temporary thing for winter.  Plus, a moisture barrier could create moisture problems inside the house by trapping moisture.  Save your money and avoid the risk. Instead, consider adding a plastic drape over the top of the bales to divert  moisture away from the walls.  The plastic could be fastened to the walls with tack strips and then pinned to the bales with wire pins .  (Old coat hangers can be cut and bent into shape very easily.)  Drape the plastic about 12" down the front of the bales.

P.S.  This is the first I've heard of using bales in this way.  Please let us know how it works out.

Q: I have property in Northern Oklahoma, can you give me recommended builders for straw bale construction (Home) in the area (Tulsa) that I could consult with?

A:(Owen Geiger) The Last Straw Journal has a Fall Resource issue each year that lists builders and other resources state by state, country by country.  This one issue will answer your question, but you'll quickly save enough from all the great ideas to pay for a subscription. www.strawhomes.com .

Q: I plan to build an 850 sq foot strawbale guest house behind my In Law's house in Tucson. It will be used as a family house for 4 people (2 adults, 2 children) for about 6 months of the year (october-april). I have no experience as a builder but some carpentry
and house re-hab experience. My plan is to purchase a wood frame pole barn structure with metal shed style roof with extra overhangs(no siding) have it erected by professionals over a monolithic concrete slab, then come in myself and pour a 6" stem wall outside of the wood frame and stack up straw bales to form the walls. Does this seem like a sensible and economical way for a non builder to have a frame put up?

A:(Owen Geiger) It sounds like you are on the right track.  Knowing your limitations and hiring out the pole frame work is smart.  You can do almost everything else and avoid the most complicated and dangerous part of the job.

Do you know of anyone who has used a pole barn structure before as the base for a straw bale home and if so, do they have a website?

Not personally, but pole frame construction is very common, meets all US building codes and is a great way to build.

Q: My question concerns the trade-offs between various natural building methods and how to choose what's best for my particular situation. I'm a 50 year old single woman with some physical disabilities, modest to so-so building skills, and little money -- but a lot of determination! I live in coastal hills of Sonoma County, Northern California, in a forest/grasslands microclimate with 100" of rain from November to May and occasional high winds (e.g., just had a storm with 80 mile winds and 6" rain in one night). Hot and dry summers, with extremely high fire risk. Oh, and just a mile from the San Andreas Fault. I love it here!

A:(Owen Geiger) Either strawbale or earthbag will work.  It's up to you.  Earthbag construction is less likely to be damaged by moisture.  Strawbale could more easily be made earthquake resistant.  Check with your building officials and see what's allowable this close to the San Andreas Fault.  I would opt for living in a safer place, but for your situation a small, load bearing structure designed for earthquakes would be the safest/best option.

Q: I am thoroughly fascinated with strawbale building and your site is wonderful.  People like you are our only hope.  I really mean that.  Please don't get discouraged. I really felt my age however, when I read in the questions and answer page your answer to the person who wanted to place straw bales around their foundation for insulation that you had never heard of that.  Ouch!  In Minnesota up into the late 1960's when I was in high school this was quite common.  I believe people would temporarily tack up roofing paper and then snake a one or two-layer track of straw bales around the house. 

A:(Owen Geiger) Thanks for your kind words.  I really appreciate it. As far as bales around a foundation, they can be used as you describe as a temporary (one-year) solution.  This wouldn't work as a permanent solution, of course.  The best solution is to design the house correctly from the beginning so these half-way measures aren't required.

Q: You have stated that strawbale should never be used for basements. But what about for a PSP type underground house (without the plastic sheeting) with the earth banks cut back to the angle of repose and French drains around the perimeter with the roof extending to cover the area between the SB wall and the excavated earth bank? The SB walls could then be constructed on top of a basement type footer and floor with a toe up as above ground. Would moisture still be a problem ?

A: (Kelly) It seems to me that as long as the bales can breath and are kept absolutely dry, then your idea should work.

Q: I was just wondering how you tested your straw house against certain elements such as fire? I would have thought that a house made of straw would be quite susceptible to damage from fire.

A:(Owen Geiger) Bales don't have enough oxygen to support combustion.  This has been known for years.  A recent fire test confirms that strawbale meets fire code.  See Bruce King's report and video at Ecological Building Network.  (Follow the orange links.)

Q: I was wondering if this practice had been used in anything other than houses? What would be the practical benefits of using bales for example in tall buildings? Maybe not the whole thing, but just a layer on the inside at vulnerable points? I am working on a Discovery Channel program that is dealing with testing and adapting new technology for future problems. Even the cross-fertilisation of existing technologies in order to improve certain things.

A:(Owen Geiger) A subscription to The Last Straw Journal will answer all of your questions.  They also have a new CD with all the back issues (40 issues, I believe). Tall buildings:  If you have a structure that carries the loads (steel, etc.) then there's no limit to how high you can build.  If the bales carry the loads, then the maximum is 2 stories (as a general rule).  However, you'll probably never see bales used in high rises because space is so expensive. Strawbales have been used in many types of buildings -- resorts, post offices, shops, schools, you name it.

Q: I´ve read quite a lot about the insulating qualities of natural materials, especially the straw bales, but everybody´s always referring to thermal insulation. What about the acoustic one? Can straw, forming really thick walls, be seriously insulating? I´m about to try it (insulating my loft´s "glass-walls" so the nearby houses don´t get disturbed by the really loud music I usually play) and I´d like to be a little certain before investing a long time on it.

A: (Kelly) Strawbales make excellent insulation both thermally and acoustically. You will be amazed at how well they do!

A: (Owen) There is a detailed report on the acoustical properties of straw bales out there somewhere.  I believe it's referenced in Chris Magwood's and Peter Mack's More Straw Bale Building.  If not, write The Last Straw and ask for the back copy that contains the report.  (It wouldn't hurt to do a Google search.)

1-How should I make the junctions, the perpendicular "encounters" between bales and concrete? A layer of an extra material? or "simply" adjusting the last row of bales by pushing? (Does not seem simple at all, to push such a heavy thing from the top of a ladder!!).

You always want to connect the bales into the top and bottom of the structure for rigidity.  No need to over exert yourself pushing.  Plan ahead so your bales will fit within the space.  Or make custom bales for the top row about one inch smaller than the opening, and then stuff the difference with thin flakes.

2-Can I cut any bale (not just the corners, but also cut in half) as long as I tie it properly? Would any chain-shaw be ok?

You can use a chainsaw if you like.  Here's a way to make custom bales without a chainsaw: Cut one twine, separate the flakes at the point you need, add new twine, and repeat for the other side.  A helper and a little practice will make it much easier than it sounds. Cutting the bales into thin slices in the other direction will most likely just make a mess.  It's easier to make custom bales as described above.

3-About how thick should the bale-wall be to provide an insulation value similar to that of a concrete wall?

Concrete is a very poor insulator - about .08/inch.  Using round numbers, strawbale has about 20 times more R value!

4-Are all kinds of straw equally adequate for building in general, and for insulation purposes in particular? The following are the types I´ve found for sale, here in northern Spain. Of course, I don´t expect a full report on all of them, but I´d appreciate any comment concerning that matter. 1- RYE 2- BARLEY 3- WHEAT 4- GREEN PEAS 5- CORN 6- DRY HERB (DRY GREEN?) 7- RICE

Rice straw is supposed to be the best, in part because of it's high silica content.  Next, I would go with wheat or barley and then rye, in that order. Bale compactness, moisture content, uniformity of bales, cost, etc. are all qualities you also need to consider. I wouldn't use the others.  Straw is better than leafy green plant material.

Q: My wife and I are located in Regina, Saskatchewan, Canada and are planning to build a straw bale house next summer. This house will have an attached garage. What we would like to do is build the garage this summer as it would provide a simpler project for us to get some experience before we tackled the larger part of the building. It would also allow us to store bales over the winter with little risk of moisture damage.

My question is are there any special steps we should be aware of so that when the second phase of the building takes place, the entire structure is properly sealed, particularly at the joints between the garage phase and the house phase? We had thought of doing the first two coats of the plaster on the garage, then building the house the next summer and when we get to the third coat, do the entire structure. Would this work?

A:(Owen Geiger) Everything sounds good to me.  You don't need to do anything special where the house and garage join.  Just use normal building common sense.  For example, make sure the wall of the house is tied into the garage with pieces of expanded metal lath, etc. so it's secure. Doing the final coat on both at the end should create a more uniform finish.

Q: Greensburg, Kansas was hit by an f-5 205mph tornado May 4th. It lost 1,000 homes, 95% of total, and 100 businesses. We need to rebuild from scratch and need help in all kinds of housing etc. First will be a need for dorms for workers to stay during the week. Then entire blocks of new housing. What would you advise? Can you attend a housing fair? We have a lot of wheat straw available locally and the town wants to build "green" like in LEED certified.

A:(Owen Geiger) First, my heart goes out to your community for your loss.  A tornado destroyed farms in my neighborhood in Iowa when I was a child and I saw the impact first-hand.

Best sources:
The Last Straw Journal: www.strawhomes.com (the Fall Resource issue lists designers, contractors, etc. by state and country)

As far as rebuilding as sustainably as possible, that's a great idea.  And strawbale building, as you know, is probably the best possible solution for your area.  It makes sense to do things right.

Q: I'm 18 and getting ready to leave my parents' place. I would like some suggestions on building a straw house. I want one big enough for me. I want one because they are, I hear, inexpensive, and environmentally friendly. I live in Indiana. Anything at all will help me, or would you know of any free plans or guides?

A:(Owen Geiger) I'm not sure if you're aware of building codes and permits, local ordinances, obtaining financing for alternative buildings, insurance, etc.  In other words, building a house (legally) is a major expense and effort.  Is this your plan?

Or are you looking for something really cheap to help you get by? Maybe a 'guest cottage' that you build on land of one of your relatives.  I'm talking about a low-cost, 'below-the-radar' (non-permitted) structure that is not legal. With a little extra effort and expense on the roof and plaster, this simple design could last for quite a few years.

Q: I am considering building a small straw bale building in Spain. It will be single story with a double bedroom, living room and bathroom, and a small porch outside with an outside kitchen. Would you advise load bearing or simple box beams with a sloping roof, (sort of Santa Fe style)? Which books are most geared to these small buildings, as the ones I have bought tend to be geared to large family homes?

A:(Owen Geiger) My favorite book for small straw-bale houses is Small Strawbale, by Bill and Athena Steen, with lots of drawings by Wayne Bingham, great photos, shows lots of good possibilities and it's not too expensive (about $20).

You can mimic almost any style, but whatever you do don't build parapets with bales.  (Parapets are exposed walls along the roof line of a Santa Fe-style building.)  They'll definitely fail from moisture damage.

Load bearing or post and beam:  Up to you.  Are there difficulties with obtaining building permits where you live?  If so, post and beam is the easier choice.  This method also creates a roof first with a shady, dry place to work.  And keeps the bales dry, which is super important.  Try to use standing dead trees killed by lightening for the posts (if codes allow this).  Also, try to add a curve here and there to jazz things up a bit.

Q: I am currently located in southern Ontario, CAN, and am looking for an employment opportunity in the field of "green homes" / alternative materials and construction. I would be willing to travel for a good opportunity for work and experience, but I have few leads to follow. I have over 12 years experience in the standard home building and renovations trade, but am looking for a more rewarding career. I would be extremely grateful if you had any advice or direction to offer someone like myself looking to make a personal and professional change for the better.

A:(Owen Geiger) More and more weekend wall raisings are available where volunteers can get some practical experience.  Some of these opportunities are listed on the Internship, Apprenticeship and Job Opportunities page at The Last Straw:

First, decide where you want to live and work, and then search local builders who are building sustainably.  Yes, it's still a niche market, but more and more companies are switching over.  Most companies are listed by state, province, country, etc. in the Fall Resource issue of The Last Straw.  You can order a back copy: www.thelaststraw.org/backissues.html . The main thing is knowledge.  Learn as much as you can.  Be sure to subscribe to The Last Straw and buy the CD-ROM.  What a treasure -- 10 years of the journal for just a few dollars.

Also, you can search WOOFER sites, permaculture forums, etc.  You could also do a more targeted search seeking employment at top firms if you're willing to relocate. In addition, I highly recommend attending natural building colloquiums, state and international straw bale conferences, and major workshops such as Build Here Now.  This will give you a chance to hear and meet the top experts.

Q: I'm doing a permaculture design project and we're wanting to incorporate a sauna. I found saunas made with the strawbale method. We're in Asheville, NC. Would you advise a strawbale sauna for our area?

A:(Owen Geiger) I know people who have built strawbale saunas and are happy with them, but this may not be the best method.  I would lean towards a method like earthbag building that is less affected by moisture.  In an extremely cold climate like Alaska, then strawbale is probably the best choice.

Either way will work, so go ahead and use what is most readily available and with what you feel comfortable doing.  If ramming earthbags isn't your idea of a fun weekend, consider Kelly Hart's method of using scoria in the bags.

Q: I'm interested in straw bale construction, but living in NC, any straw I used would likely need to be trucked halfway across the country. On the other hand, there are plenty of pine trees, and baled pine needles are readily available for landscaping use. Has there been any research into the viability of pine needles as a building material?

A:(Owen Geiger) I have heard of using pine needles, but I don't see how you could make 'custom bales' to fill in the small areas.  Some type of grain is grown almost everywhere, so I would look into using whatever is grown closest to you.  Check with feed stores.

Q: I'm making my master thesis in architecture and the topic is: "Self-sufficient house". I would like to design a straw bale house, but I can't find any technical information or drawings about foundations, walls, roof, like for example, key junctions between wall and roof. Do you know where can I find it?

A:(Owen Geiger) Chris Magwood's book is by far the best.  It has dozens of AutoCAD drawings showing various possibilities for each part of the wall.  Straw Bale Details A Manual for Designers and Builders   by Chris Magwood and Chris Walker.

Q: I own property in Michigan's eastern upper peninsula. It's an old hay field with very heavy clay soil, no sand anywhere close. I'm interested in building with these materials. The hay consist of timothy, birdsfoot trifoil, and other long tall grasses. Can I use just the clay and hay for building?

A:(Owen Geiger) The first bale buildings constructed by the pioneers in western Nebraska were built with prairie grasses similar to what you describe, so this is a possibility.  However, the preferred choice is to use bales of straw that are tightly compacted.  Grass will rot/decompose more readily than straw.  In addition, grass can be fed to livestock, whereas straw is considered a by-product of grain production.

Q: I would like to find out if it make sense to build a Pet Resort with Strawbale construction. I was worried about using the cleaning with water and chemicals getting on the walls and deteriorating them. I guess some type of coving could be put at the base.

A: (Kelly) I see no reason why you couldn't construct a Pet Resort with strawbales. I might suggest that in this instance you start building the strawbale walls well above the floor level, using a stemwall of earthbags filled with gravel to avoid issues of water wicking into the strawbale walls.

Q: I am not building a natural home. I'm doing regular construction. My problem is that because of budget constraints we were unable to get heating installed and construction has come to a halt. I live in Iowa, so frost heave is of great concern. Is there a way to use strawbales to help protect our foundation from frost heave? There is 5 inches of insulation on the foundation walls (it is an insulated concrete form) and it goes all the way to the footing. We do have 2" of EPS under the concrete slab in the basement. We also have drains around the footings with about 3 ft of pea gravel on top for drainage. I would really appreciate any information you might have on how strawbales could be used to frost protect our basement through this winter.

A:(Owen Geiger) You should be okay even without bales, since I'm assuming this is a code approved home with a foundation built below frost line.  And hopefully the soil around the house isn't saturated, high clay content or has expansive clay.  So there are a number of variables that can impact things.  I'd talk to your foundation engineer, who will know your local conditions.  It wouldn't hurt to add bales around the perimeter for extra protection and then recycle them in your garden and lawn next year.

We weren't concerned about not having heat this winter because the house seemed fine last winter without any heat. But a few contractors that we've been speaking to for some work keep telling us that our house will be in trouble if we don't heat it this winter, and now they have us worried. If we added strawbales to the perimeter, would you have any idea how far out from the walls we should cover? How deep should the bales be? Would we need to fill the basement floor inside with bales too?

I'm not sure what to say, actually.  You made it through one winter just fine.  Why would it be different this year? But hearing warnings from a chorus of local builders is very worrisome.  One person may not know something, but group consensus is powerful because it has grown from the school of hard knocks, as they say. Like I said, you could add a row of bales around the perimeter.  I don't know if adding bales all around the inside would help much.  It doesn't hurt to get the concrete cold.  You're trying to stop the expansion of the soil underneath. 

Q: Can the jumbo corn stalk bales be used as infill the same way as straw bales? In northern Colorado these are widely available. Jumbo bales would make quicker work of a wall, not to mention the R value of the jumbo bales.

A: (Kelly) I have seen at least one house built with jumbo bales of straw. This was done by SunRay Kelly, and as I recall he used a crane to pile them up. They certainly did provide ample insulation. I have never heard of the use of baled cornstalks for building, so I can't say how well they would perform. If they were tightly baled they would also provide a great deal of insulation. My main concern would be durability, not knowing how long they would last, since they may rot over time unlike grain stalks. I expect that they would have to be completely dry, otherwise you might end up with a wall of silage!

Q: I'm considering buying a beautiful strawbale house built 1997 on Salt Spring Island BC on Canada's west coast. There are cracks all around the outside which are larger than hairline. Is there any technique, probe, tool that can give us answers as to the integrity of the building?

A:(Owen Geiger) There are moisture probes that might fit through the cracks. Checking for moisture damage is the main thing. Not sure about optic probes. There's probably something available that would work. Call all the home inspectors in your area. And of course, if you buy the house then seal all the cracks as soon as possible.

Q: I came across your site on straw bale building and wonder if you share your knowledge about the feasibility of building straw bale temporary shelters for those braving the cold in North Dakota and Iowa to stop the Dakota pipeline.

A: (Kelly) Strawbales make great temporary shelters. They go up quickly by just stacking the bales, and with a little ingenuity you can make a roof with a tarp. See http://greenhomebuilding.com/articles/nbc03.htm for a photo and description of just such a shelter.

Q: How do I do an earthen floor in a strawbale building?

A: Earthen floors may be "poured" or tamped into place, with the final finish smoothed with a trowel and typically sealed with linseed or tung oil.  The more moisture used in the mix, the longer the floors will take to dry, the more they will shrink, and the more cracking you can expect in the floors as they cure, just like with a concrete slab.  With earthen floors, as with concrete, there are benefits to introducing "control joints" which provide a controlled place for the shrinking to occur.  So, if choosing earthen floors, rather than creating a "monolithic slab" of earth, you might finish the floors room by room, using the bottom plate of the interior walls as part of your "control joint" system.  Earthen floors have many benefits: they are low in embodied energy, wonderful to walk on, and can be amazingly beautiful, but they are not "dirt cheap."  You will find they take more skill and probably will cost more than concrete. 

Q: I'm wondering if you've seen any methods for straw bale construction which use a 'hardening agent'? We're thinking that spray or dipping the bales in the right solution will harden them like bricks and also create fire and mold resistance.

A: Generally speaking, straw-bale building is structurally sound and fire resistant, simply by being plastered with stucco, lime or earthen plaster.  Mold can be avoided by protecting bales from moisture (rain, plumbing leaks, etc.) through the delivery and construction process, and with appropriate design for the local climate.  Humidity is not generally an issue, unless moisture vapor condenses inside a wall.  So far architects, engineers and code officials have not found it necessary to harden a bale into a "brick."

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