Building a Straw Bale House

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A two story straw bale greenhouse.
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Solar windows help increase energy efficiency.
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Even kids can help with the construction.
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Construction of the greenhouse.
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Constructing the house's skeleton.
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Hammering nails to hold chicken wire in place.

If you want to build a new house out of wood, you’re in for
sticker shock when you reach the lumberyard. Lumber has
doubled in price in the last year alone, and prices may
continue to rise as old growth forests dwindle and/or more
areas are declared off-limits to loggers in order to
protect endangered species. A 2 x 4 that cost approximately
$1.50 last summer now runs as high as $3. Faced with an
increase like that, a builder must choose between waiting
out the building season or constructing a much smaller
house for the same price. A growing number, however, are
driving past the lumberyard to pick up their housing
materials at the local feed store-stuffing their walls with
straw bales and avoiding wood when they build their new
homes. In the process, they are saving a wad of cash.

You can build a home for as little as $4,000 by using
plastered straw-bale construction techniques instead of
wood in your walls. In many parts of the country, straw
bales can be bought off the farm or feedlot for as little
as 504 per bale, especially in areas of the country where
straw is considered waste and is burned every year.
Building techniques are simple, forgiving, and easy to
learn. In fact, the most difficult part of straw-bale
construction may be getting past the mythology of the
“Three Little Pigs,” which maligns straw as a shoddy
building material.

Nebraska Roots

Matts Myhrman and Judy Knox know all too well about
people’s skeptical reactions. These plastered straw-bale
construction pioneers publish The Last Straw, a
newsletter that reports on techniques and tips for building
homes out of straw bales. The two travel the world talking
the praises of these homes, taking inventory of straw-bale
houses built around the world and directly addressing
people’s questions and concerns.

In their travels the two discovered that buildings have
been constructed with straw bales in this country ever
since necessity spawned experiments in Nebraska at the turn
of the century. In the state’s Sandhills, located in
northwestern Nebraska, early settlers turned to an abundant
resource (straw) to replace a scarce resource (wood) for
their homesteads. At the same time, hay balers were just
coming into common use on farms in the area.

Most of these homes were like the one built by Leonard and
Tom Scott–a three bedroom, two-bathroom,
900-squarefoot house with a 600-square-foot basement that
was finished in 1938. Many homes in Nebraska towns such as
Alliance, Arthur, and Dannebrog that have been built from
straw bales are still standing today.

Plastered straw-bale construction was also used for other
structures such as farm buildings, schools, offices, and
grocery stores. However, many Nebraskans were concerned
that they weren’t living “civilized” existences in straw
homes; so when wood became easily attainable again in the
area, home builders resorted once again to traditional
stick houses.

Correcting Myths

Critics of straw-bale construction–many of whom would
prefer builders use wood, brick, and blocks for their
homes –can tick off a list of potential hazards with the
material. They first point to the fire hazard of straw, a
combustible material in walls. Actually, straw bales are
safer than wood because the bales are compressed and tend
to smolder if exposed to fire.

In a test of the fire rating of a house built with straw
bales by the National Research Council of Canada, the
plaster surface withstood temperatures of about 1,850°F
for two hours before any cracks developed. According to the
Canada Mortgage and Housing Corporation, “The straw
bales/mortar structure wall has proven to be exceptionally
resistant to fire. The straw bales hold enough air to
provide good insulation value, but because they are
compacted firmly, they don’t hold enough air to permit

Straw-bale homes can burn just like any other house though,
and special attention must be paid to electrical wiring
details. Adding a firebreak at the top of the walls can
preclude the threat of lightning-caused roof fires or
chimney fires. Fires in older homes present problems not
because they spread quickly but because they smolder and
are difficult to extinguish. According to Matts Myhrman,
“Trying to burn a well compacted bale is rather like trying
to burn a phone book.”

Another worry is that straw walls will offer tempting
nesting sites for mice and other vermin. But in plastered
straw-bale construction, the straw bales are enclosed in
plaster or stucco and offer no more enticement to pests
than a framed wall enclosed with drywall.

In addition, homes built with straw bales may substantially
reduce your energy bills. Straw is a natural form of one of
the most common residential insulations in use in homes
today: cellulose. Because bales are compact and
approximately 20″ wide, they can result in thicker than
normal walls with high R-values, even more so when proper
insulation is added.

R-values, a measure of a material’s thermal resistance (how
well it resists heat passing through), are established by
the American Society of Heating, Refrigeration, and
Air-Conditioning Engineers (ASHRAE). This nonprofit
organization holds more than 50,000 engineers and others;
they establish these standards in order to encourage the
adoption of energy-efficiency measures and provide
standards with which to evaluate the industry practice.

Straw’s actual R-value is approximately 2″ to 2 1/2″ and
can result in R-values of close to R-40 in walls of
20″-wide bales. This stacks up pretty well compared to some
of the more conventional forms of insulation. For instance,
loose-fill cellulose insulation has an R-value per inch of
approximately 3.5. Fiberglass batting has an R-value per
inch of approximately 3.2.

Normally, home builders settle for less and would not even
consider insulating a wall to the level of R-40 because of
the high cost of materials. It’s important to note that the
doors, windows, and ceiling are independent of the
straw-bale construction and call for their own insulation.
(For some suggestions, see “Home Insulation for the 1990s”
on page 45.)

“The insulation factor of straw bale is definitely the key
for us,” says Athena Steen, who lived in a straw-bale house
for five years in New Mexico before moving to Arizona. Her
present house, which is adobe, came with the property she
now lives on, but she plans to build another straw-bale
house soon. “The straw-bale house stayed a lot cooler
throughout the summer and a lot warmer during the winter.
We heated our house with wood, and we used approximately
half a cord for the whole winter. In a frame house we would
have used at least a full cord.”

Even more energy savings is possible when solar gain is
incorporated into the home’s design. The Steens, for
example, used south-facing glass and adobe interior walls
to catch and store heat from the sun.

Catherine Wanek of Kingston, New Mexico, built a wall of
double paned windows facing south that collect the low
angled winter sun when she needs extra heat. An opaque roof
reflects the overhead sun above. Catherine kept the east
and west walls solid straw bales, except for the doors and

Appealing Features of Straw Bale Homes

Old-timers in Nebraska straw-bale homes have commented on
how quiet these homes are inside, due to the thick walls.
This is true even when the houses face howling prairie
winds. Modern straw bale structures are no less quiet, and
are probably more so thanks to better-built windows and
doors today.

Just ask the Steens. They had a creek in front of their
home that would roar loudly when the water was high. “When
we went inside the straw-bale house, you couldn’t hear the
creek at all,” says Athena.

Many feel that the most attractive aspect of building with
straw bales is the potential savings that comes from using
such inexpensive material. Bales are available in most
parts of the country ranging from a cost of $1.50 to $4 a
bale for those that are delivered to the building site.

A comfortable home of 2,500 square feet would require
approximately 400 bales. A house built with wood studs that
would have cost roughly $30,000 can be built for as little
as $5,000 using the straw bales. Of course, these prices
assume that you will be building the entire structure the
old-fashioned way–yourself, recruiting family,
friends, and those who want building experience for free.
Costs could jump a couple of thousand dollars if you
decided to hire outside labor for the building and

As for its strength and durability, straw in bales has been
tested both in the laboratory and out in the field. The
proof is in the pudding: Houses built with the bales more
than 90 years ago are still standing strong as ever today.
In fact, one house located in Wyoming withstood an
earthquake that registered 5.0 on the Richter scale,
indicating that straw may just be a more desirable building
material for areas that are susceptible to earthquakes.
That house is still occupied by the same family, Charles
and Mary Bruner and their son Phillip, who was born there
and grew up in that house.

“The earthquake was in the 1970s and it was either 5.3 or
5.8, I’m not sure. But I am sure there wasn’t a single
crack in the house,” says Phillip.

The Bruners built their straw-bale house in 1949, the year
Phillip was born, as a “temporary” residence; they’ve been
living there ever since. Charles Bruner got the idea from a
neighbor who had built a storage shed using straw bales.
When asked what it was like to live in their house, Phillip
Bruner replies enthusiastically.

“You can live in this house comfortably during the summer;
it stays nice and cool. We have never needed any air
conditioning, and in summer we get days up in the 90s.
Also, last winter I only turned our small bedroom heater on
twice. If I had to guess how our utility bills compare to
those of our neighbors, I’d have to say our bill is about

Compression tests have also demonstrated that straw-bale
walls can handle compressive loads several times greater
than standard wooden walls. In Tucson, Arizona, a more
detailed study is currently underway to examine the results
of tests that showed that one single bale could withstand a
load of 10,000 pounds per square foot. This would be
similar to one straw bale supporting the weight of two
dozen pickup trucks without breaking.

Working With Bales

Building a home with straw bales isn’t rocket science. Some
feel the biggest plus is the pride obtained by completing
the labor without professional help. Catherine Wanek would
be the first to agree. She built her dream greenhouse
addition to her bed-and-breakfast lodge with the help of 20
people–all friends, family members, and those who
simply wanted to obtain hands-on experience.

“I was inspired after hearing about the success of Kate
Brown, a New Mexican potter who built her own straw-bale
studio;” Catherine says. She put her structure up in two
days–roof and all–mainly with the help of women
all over 60. Talk about empowering!

Even the most difficult techniques can be learned in less
than two weeks of study, and the majority of knowledge
needed can be gained in a few hours. There are two basic
approaches: using the bales to build load-bearing walls, as
the early settlers of Nebraska did, and using post-and-beam
construction to take the load off the walls, which is
preferred by code officials.

The straw bales are stacked in interlocking rows like
bricks and are often secured to the foundation with rebar,
usually one or two pieces per bottom bale. Then the rest of
the bales in the wall are secured using rebar pins or
wooden dowels. The bale walls should then be covered with
chicken wire for further reinforcement.

The last step is to smear the mesh with stucco or plaster
as finishing. Some builders have opted to leave their
straw bale structures unfinished, but these have often been
temporary outbuildings. It’s a bad idea for a permanent
structure because it invites problems with fire, nesting
pests, and the unwelcome feeding frenzies of horses, cows,
deer, or elk.

Of the more than 100 plastered straw bale homes built in the
United States so far, most have been constructed in rural
areas of the Southwest beyond the jurisdiction of
building-code officials. Meeting local building codes may
not be a problem for plastered straw-bale homes planned for
rural areas, but it’s important to work with local
officials if you plan to build in zoned areas in larger

Because straw-bale homes are different, code officials will
need to be convinced of the building material’s durability
and safety. As David Bainbridge, restoration ecologist and
adjunct faculty member at San Diego State University,
points out, if log homes had not been built in this country
for more than a century, they probably wouldn’t be allowed
by many building code officials as well.

Bankers and insurance companies are another group that home
builders often have to work with if they want to obtain a
mortgage, financing for building or later selling their
home, or home insurance. A plastered straw-bale home,
especially one that is built without load-bearing walls,
should meet the same codes and qualify for the same
insurance coverage that covers other framed, stucco-covered

Another possible approach, due to the low cost of building
a house with plastered straw bales, is to avoid the need
for a mortgage by saving and paying as you go. The original
straw-bale homes were built where banks were as scarce as
wood. As these homes become more common, however, both code
officials and financiers should look more favorably on

Construction of a Straw Bale House

Step 1.

The best way to start any house is by drawing up a floor
plan to visualize how your straw-bale house will look. Then
you should practice construction by building a model of
your home out of Styrofoam (a great way to reuse it). This
should be completed before you even begin to
select your bales. After all, it’s much better to make
mistakes carving up your polystyrene model than to find out
your idea won’t fly halfway into building a wall section.

When you have worked out exactly how you want your house to
come together on the model, it’s time to pick out your

Step 2.

Locate a source of straw bales in your area. Bales are
usually widely available from local farmers, ranchers, or
feed-supply stores about the middle of June, when winter
wheat is harvested. Says Catherine Wanek, “Finding bales in
August turned out to be rather difficult. At one point I
even contemplated shipping in straw from Arizona or
Colorado, but I finally located a pile of oat straw in New
Mexico about 80 miles away. I’d recommend people search out
a local farmer before he harvests and having him deliver.”

Straw, usually wheat, oats, or barley, may include other
grasses such as rye or wheat grass. Check the bales you
intend to use, making sure they are dry and compact. When
you negotiate the price of your bales, make sure the
delivery to your budding site is included in the cost.

Step 3.

Your next step is to make the concrete footings for your
house. These footings should be made to the dimensions of
your bales. For example, you will need an 18footing for a
two-wire bale footing. If you err one way or another, it is
better to make the footings bigger. Then, you can fill any
gaps with loose straw.

If you want, you can also use bales as the form work to
contain the wet concrete for a footing. Be sure to consider
your plumbing needs before you pour any concrete. Here
again is where it is better to think through the details
with your model instead of when pouring concrete. While
waiting for the concrete to set, turn your attention to
getting ready the top plates and any framing for doors and

Step 4.

Put up temporary corner braces at each corner of the house
to help keep the walls plumb while you put them up. Seal
the footings and raise the bale walls placing window and
door frames and adding any wiring detail at this time. For
the walls, the bales are staggered like bricks starting at
the corners. The bales are then spiked together with rebar
or wooden pegs.

One method is to peg each bale above to the bale beneath.
Another method uses long rebar secured in the footing.
Bales are then skewered like shish kabobs onto the long
metal rods. Some builders carve out their windows at this
step by cutting holes in the bale walls with a bale saw or
chain saw. It should be noted that there is no one
definitive approach to this type of construction-builders
are constantly coming up with creative approaches through

Step 5.

When the walls are in, it’s time for the top plate. Be
careful to straighten the walls here where needed as the
top plate is installed. Next, place the trusses and roof
supports on top of the top plate, and then add the roofing.
If you intend to have an attic, this is the time when you
should insulate the attic and put up the ceiling. Your
house is now safe from the weather and you can concentrate
on the details such as your floor, windows, and doors, and
any wiring details that still remain to be finished.

You may wish to let the structure sit for two weeks to a
month after putting in the walls so that you will be able
to watch for any settling. Others may wish to move right
along to the next step, which is to secure the top plate
and roof to the footings. Then cover all of the straw walls
with netting or 1″ chicken wire before adding the finish of
cement plaster and stucco.

Step 6.

Before you build your own plastered straw-bale house, talk
to someone who has already gone through the process. The
next best thing is to start with a step-by-step guidebook,
such as A Straw Bale Primer, available from its
author, S.O. MacDonald, for $10. Write to MacDonald at PO.
Box 58, Gila, NM 88038.

Construction details that include drawings and specific
answers to construction questions are also available from
consultants Matts Myhrman and Judy Knox of Out on Bale
Unlimited (602/624-1673).

One especially useful booklet available from them is
“First-Aid Kit for Plastered Straw-Bale Construction,”
which shares the lessons they have learned by building
straw-bale homes.

Another good manual that contains construction details is
Plastered Straw Bale Construction, by David
Bainbridge with Athena and Bill Steen, which is available
for $12 from The Canelo Project, HCR Box 324, Canelo, AZ
85611 (602/455-5548). This manual contains an extensive
bibliography on the technology of straw bale construction.