The Building Blocks of Straw
Renewable building material offers energy savings and longevity.
by Anne Pyburn Craig
Straw bale building got its start on the plains, where
timber wasn’t easy to come by. What was available—straw and mud—stood the test
of time. The invention of the mechanical baler in the mid-19th century meant
that there was a handy supply of these nifty sustainable building blocks, and
more than a few of the resulting structures still stand today.
Those early pioneers probably never imagined that straw bale
construction would ultimately inspire a wave of innovation. The 1930s saw a
decline in straw bale building as cement took over for a while. But the
technique’s advantages remained hard to top, and it began to be reintroduced as
late-20th-century humans sought energy-efficient and nontoxic ways of building
nests.
“A couple of people out in the southwest found an article
about it and decided to build one, and started a whole movement without
particularly trying to,” says natural builder Ben Simpson of Rosendale. “People
who saw it wanted one, the idea spread, and pretty soon it was being written
into building codes.”
Something about the common-sense nature of straw bale
construction—using a material that would otherwise be burned as waste and
provides a built-in R-factor of over 35—seems to bring together traditionalists
and zero-energy fans in a happy convergence. One of Nebraska’s latter-day creations,
a bar built in 1996, is christened Angels’ Straw Bale Saloon and features the
story of its eco-friendly construction prominently on its website (“a
time-consuming process as all labor was provided by the owners and funding was
minimal”) next to the links to Bikefest photo albums. One tough place, you
might say, built by the children of the original proprietors after the earlier
incarnation was flattened by a tornado—take that, Three Little Pigs.
In the Hudson Valley and Catskills, straw bale building has
been the mode of choice for several showplace structures and a good sized
handful of green homes, though still rare enough to garner feature write-ups in Chronogram and the New York Times. For every frequently raised question, straw bale
folks have a ready answer: the structures are, if anything, more fire-resistant
(and far less toxic) than typical post-and-beam fiberglass-insulated ones; and
clean, dry, dense straw is extremely resistant to vermin and insects. More than
one local building inspector has begun as a skeptic and come away a convert.
There are two distinct methods in straw bale construction.
Straw can be used as infill and insulation for traditionally framed stick-built
houses, or serve as a load-bearing structure (“Nebraska style”) in its own
right. Once the walls are built, some sort of mud mixed with straw is used to
create the sheathing.
When they needed a multipurpose agricultural building on
Four Winds Farm in Gardiner, Polly and Jay Armour hired Simpson to build it of
straw. It was only the second such structure that Simpson had created, but his
sense of purpose as a builder dovetailed beautifully with Four Winds’ mission
of sustainable agriculture. In about two years, the farm’s community supported
agriculture (CSA) operation had an office/greenhouse/root cellar space to be
proud of.
“We’re very
satisfied with it,” says Jay Armour. “It’s super well insulated, no auxiliary
heat needed. We have a CSA that operates here, and they distribute there in the
heat of summer; you walk in, you’d think there’s AC. And as we harvest it’s
nice to have a cool space to bring it into. A lot of people think in terms of
reducing the energy they need for heating, but cooling is also a big factor,
especially in agriculture...We’re looking at trying to reduce our carbon
footprint as much as we can, and I know that building has helped. It’s eleven
years old now, and aside from the dust—which has nothing to do with the straw
bales—it looks as good as new.”
“A lot of people
get the silly idea in their head that straw will rot or fall apart,” continues
Armour. “No. Packed really tight and covered with stucco, it’ll last
indefinitely—probably longer than stick-built.”
Simpson came to his calling in sustainable, collaborative
construction via a somewhat roundabout route: a geography major and cartographer,
his fascination with the Earth and its places led him to wanting to build
environmentally sound and human-friendly dwellings on it. Straw bales are one
of several materials he uses as sole proprietor of Your Growing Places.
“I love working with straw and earth plasters, blending
those with more conventional techniques whenever I can,” Simpson says. “It’s
really nice material and lends itself to curves and creativity. I think that’s
part of what people are attracted to, besides the energy advantages.” In
addition, he says, it’s fun and more user-friendly than conventional piles of
sheetrock and two-by-fours. “On the Four Winds project, we had a bunch of high
school kids from the Bruderhoff come down with trowels and hawks and just jump
up on the bales and jump in. A lot got done, a lot got learned, and we had a
blast…Clients can invite their friends to come out and help out, which isn’t
something you can really do on a stick-built home.”
“Straw bales are a natural, safe,
locally available and annually renewable material,” Simpson wrote in an article
he authored on the subject during the Four Winds project. “Homes built using
this technique offer insulation values of up to R-45 and can be constructed
using unskilled labor. This technique also helps to support local farm
economies, reduces fuel dependence, is economical, can last 100 years or more,
and creates beautiful and comfortable spaces. When combined with a passive
solar heating design and super efficient appliances and lighting, it’s possible
to move towards a zero-purchased-energy home.”
Since Four Winds,
Simpson has worked on a wide variety of other projects including a load-bearing
house in Kerhonkson. “Load-bearing is less common in wetter climates because
all of the bales need to be placed before the roof goes on, meaning there is
more risk of the straw getting wet during construction. It can be a challenge
in our climate,” he says. “I spent 45 minutes a day tarping and un-tarping. But
hey, they heated the whole 1,400-square-foot house with three-quarters of a
cord of wood—I’d do it again if someone asked.” Other projects have included a
straw-bale recording studio and an 800-foot addition on a house in Rosendale. “It’s
all polished logs and local hardwoods and a great big earthen fireplace
surround. I think it may be the nicest one yet.”
Perhaps there is something inherent
in the compressed blocks of vegetable cellulose and the wheelbarrows of clay
mud that will keep the rules looser and more flexible going forward. Simpson
collaborates at length with his customers through every phase of design,
permitting and building, as does North Catskills straw bale wizard Clark Sanders.
Sanders, a former veterinarian, has been building with straw since the 1970s; one
of his better-known projects was a house for his ex-wife. She’d divorced him,
but still hired him; reports suggest she’s never regretted it.
"Ultimately if we (the
client and I), have done our job well, we will have sculpted a home which
embraces, soothes and protects the occupants while providing refuge from the
inherent stresses of life,” says Sanders on his website, sounding a lot like
Simpson. One suspects that the denizens of Angels’ in Nebraska, though they
might not put it that way, enjoy a similar sensation—as do the Habitat for
Humanity clients who’ve helped build their own straw bale houses in the
Southwest. Simpson and his fellow sustainable builders would like to see the
method employed in impoverished parts of the city of Buffalo, too.
The rules are still being
written, but the limits may never be found.
To learn more about straw bale construction, visit www.strawbale.com or www.yourgrowingplaces.com.
Posted by Chris Hewitt
on 6:33 PM.
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