I'm Building My House Out of Straw

[Jim Gray]

I'm building a straw bale house in the Hill Country of Central Texas.  I've been sharing my experiences and some pictures with a few board members, and they have encouraged me to share it with everyone on the site. 

I keep a "photo essay" on flickr that will walk you through what we have done so far.  I update the pictures about once a month when we complete major milestones.  Here's a link to the photos.   If you click on the large photo to the left, you can scroll through them in order.  This first batch might not be too interesting, but I think you will find the later pictures interesting.

http://www.flickr.com/photos/18026287@N00/sets/72157624928553512/

A few years ago, my kids moved out to go to college.  My wife and I were left with a huge house that no longer fit our lifestyle.  I wanted to go smaller, simpler, more efficient and green.  I spent a year researching options including straw, insulated concrete form (ICF) and cobb.  After speaking to green builders, green architects and people who had built and lived in these homes,   I chose straw because it seemed to offer the best compromise of being green, affordable, energy efficient, nice looking and durable.

• straw is a very "green" choice -  a renewable resource that's available locally and doesn't require significant transport.  It's not hay that can be used as fodder, so it's often just burned in the field.  Makes more sense to utilize it for building.  Cobb has similar green characteristics.  ICF isn't very green....
• straw was affordable - it's not cheap, a little more than traditional stick and frame; but it's was less than ICF with less labor than cobb.
• straw buildings are very energy efficient - the walls provide the equivalent of r55.  We have matched that with 12 inches of soy-based foam for insulation in the rafters, a reflective metal roof, energy efficient windows and an energy efficient air system.  Cobb doesn't have the same properties.  ICF offers good energy efficiency too.
• straw is aesthetically pleasing - the walls are 18 inches thick, so you have deep doors and windows with soft corners.  I really like the look and the architecture fits into the Central Texas Hill Country where we are building.   Cobb is similar.  ICF has a cold sterile look to me.
• straw homes are durable - straw bale buildings in Nebraska are over 100 years old and still in good shape.  They recently opened up the walls of one and the straw in the bales was still a bright gold, just like the day the walls were laid down.  ICF would have been the best choice here.  Those houses can take a ton of punishment (fire, hurricane, tornado).

If you have any questions, just ask.  It's been an exciting journey for us, and I enjoy sharing it.

[Sunstroke]

The photos of the construction are just mind-blowingly cool. I'm not usually much for wanting to do that sort of epic project myself, but following the progress as it's gone along makes me want to build one as well.

[Buddhagirl]

This is very cool. I would love to have sustainable housing and find all of this stuff really interesting.

[StL FinFan]

Wow I am impressed!  I do have a few questions:  How do you keep rodents out?  It seems that straw would draw them in.   Are all the other construction materials standard or have you used some that are also not as common?  Is there a higher fire risk?  Is the straw specially treated somehow?  Ok I'll shut up now.

[Jim Gray]

Wow I am impressed!  I do have a few questions:  How do you keep rodents out?  It seems that straw would draw them in.   Are all the other construction materials standard or have you used some that are also not as common?  Is there a higher fire risk?  Is the straw specially treated somehow?  Ok I'll shut up now.

Ask all you want, I enjoy talking about it.

How do you keep rodents out?  Since it's straw and not hay, there is no nutritional value for rodents, so they don't go in searching for food.  They could nest in the walls, but the bales are tightly packed and it wouldn't be easy.  The biggest reason you don't have rodents and insects is that the bales aren't exposed.  They are covered by several inches of earth plaster.  The earth plaster is made up of clay, sand and straw.  It's really, really hard......so hard you can hit it with a baseball bat.  The bales are stacked on 2x4 frames that are filled with pea gravel and borax.  The borax keeps the bugs out.

Are all the construction materials standard? It's a mix of standard material, and some that aren't commonly used.  Stuff like bamboo for wall supports and clay for earth plaster. Even with the standard stuff, we are using it differently than you would see in traditional building.  For instance, the concrete we are using for the slab wont be covered with any other flooring. We scored and finished it to look like tile.  We used both stick and frame (standard 2x4 framing) and post and beam.   The post and beam wood is locally harvested cedar.  We are recovering grey-water from the sinks and laundry.  This is used to water the landscape.  We are using a spray in soy based insulation for the roof.  We wont have a well or city water.  For all of our water use, we are recovering rain water and storing it in a 15K gallon tank.  This water gets treated with a fairly sophisticated filtering system before we use it.  (rain water recovery is really cool, great quality).  Finally, I've got a regular septic system and standard toilets; but I'm also doing something with composting sawdust toilets.  It's a little out of the ordinary and would take a lot of time to explain.  Suffice it to say, I've been experimenting with it on the property for 6 months.

Is the fire risk higher? During the building process when you have tons of loose straw all around the house, there is a serious risk of fire.  You have to manage this by banning all smoking and camp fires on the property.  Once the bales are in and plastered, the risk of fire is much lower than a traditional stick and frame house.  The bales are so tightly packed, there's not enough oxygen available to do much more than singe the bales.  This has been thoroughly tested by insurance company laboratories.

Is the straw treated? Nope, it's just regular bales of straw. You do have to make sure the moisture content in the bales is low.  It's usually not an issue, but we measure the bales to make sure.  As I mentioned earlier, there is borax under the bales to keep insects from coming in; but that's it.   

The biggest risk to straw bale isn't fire or rats or bugs......it's water.  We used an architect and crew that specialize in straw bale building.  They carefully go over everything to make sure that no water can get into the bales.  We have a metal roof, with big overhangs to protect the walls, and the external covering is a lime plaster that repels water.

[Buddhagirl]

Since water is the biggest issue, would this type of house not work in a wet/humid area like South Florida? (Just curious.)

[MaineDolFan]

Jim - you mentioned fire.  I think of straw as easily burned, am I wrong?

[AZ Fins Fan 55]

This is really awesome. I was amazed looking at the pictures as I have not seen anything like this before. I am looking forward to more photos until the product is finished. Not that I want to know what you are paying for all of this but in comparison to a standard house of equal size what is the initial difference in cost?

[Jim Gray]

Since water is the biggest issue, would this type of house not work in a wet/humid area like South Florida? (Just curious.)

I've seen literature that says you shouldn't build in humid environments, and I've seen an equal number of sources that says you can.  I think it's probably okay, as long as there is air circulating freely around the outside of the house, and there is zero chance of flooding.  There are straw bale buildings in all climates, with many in the southeastern US.  I read about a government building in Alabama that is 2 stories and made of straw bales.  It's over 100 years old.  I think it was originally a county courthouse, and now it's a museum.  There are also a lot of bale homes in the Northwestern US, which I think can also be very humid.

In Louisiana, they were experimenting with rice straw, thinking that it might be more resistant to rot in a humid climate.

[Jim Gray]

Jim - you mentioned fire.  I think of straw as easily burned, am I wrong?

Loose straw burns easily, and since there is a lot around the property, we have to be very careful during the building process.  The bales themselves are fire resistant.  Mainly because they are packed so tightly there is no oxygen to keep a fire burning.  Straw bales homes have much less fire risk than conventional homes. 

[Phishfan]

This is very cool. I can't wait for you to invite us all over and see the finished project. 

[Jim Gray]

This is really awesome. I was amazed looking at the pictures as I have not seen anything like this before. I am looking forward to more photos until the product is finished. Not that I want to know what you are paying for all of this but in comparison to a standard house of equal size what is the initial difference in cost?

Thanks.  The cost is comparable to conventional building.  You could do it for less if you are willing to put in a lot of sweat equity.  The work requires some skill, but the real expense is all the labor that goes into a bale home.   Initially, I was hoping to spend a lot of time working there, but a change in jobs made that impractical.  Fortunately, I found a local crew with a lot of experience.  They live in tents on my property while they are working (Mon - Fri).  They have a large outdoor kitchen with a couple of refrigerators, ovens, sink, etc. (and a dedicated cook). They even have an outdoor movie screen for evening movies.  By living there, they keep the overall cost down, and they don't have to spend a lot time traveling, which is important since my property is several hours from their home base.

If you saw them, you would think hippies or gypsies are squatting on my property.  Their looks are deceiving.  The crew chief is a certified architect from Rice.  Another has a Masters in bio chemistry from Baylor.  They could be making a lot more money, but they are passionate about alternative building and they would rather do this than work in an office.

[AZ Fins Fan 55]

I forgot to add that using the colored concrete and scoring it to look like tile was a brilliant idea I had never seen and was really impressed with the overall look of it.

[Buddhagirl]

This is cool. I'm a (not so) undercover neo hippie type and would love to do this. When is the projected finish date?

[MyGodWearsAHoodie]

When it is done send me your address...I am mailing you a copy of "The three little pigs" as a house warming gift.