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| Build a bale of living: Straw houses are economical and efficient (March 2008) |
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By Dale McDonald
Straw houses are economical and efficient
The before and after photos of David and Stephanie Adamson’s house could not be more
striking. The after photos reveal a quiet, peaceful, beautiful home wrapped in earth tones
and natural finishes. The before photos
begin with a shocking pile of mud and straw, with a small army of helpers creating more chaos than calm.
To build a straw bale house, that’s just the nature of the business. And for Adamson it is his business. As the owner of EcoBuild, this Boulder, Colo., consultant is one of the favored few who put their money behind their convictions
and live them. From the straw bale walls
to the cork floors to the Aspen-wood trim,
Adamson’s house is as green as they get.
"The idea of a net zero impact home,” he
says, "is to use products like recycled wood
and natural clay plasters that are low energy
and also add beauty. Then, with photovoltaics,
you produce your own electricity."
Philosophy. For the Adamsons, their home is part of their philosophy, and that’s where planning started. What they didn’t need was just as big a part of the finished product as what they wanted. Self assessment matters.
"Here are some questions every home
builder should ask," he explains. "Do you
really need a spa tub? Do you really need a master suite, a three car garage, and 5,000
square feet? Do you really need an extra bedroom
that is almost never occupied? Those
things are environmentally costly.
"We don’t even have a furnace or air conditioner.
Instead, we have excellent insulation
and a large thermal mass that soaks up the
sun in winter and releases the heat slowly.
In summer, proper orientation of the windows
creates shade. If you have those things,
there’s very little need for secondary heating
and cooling. So instead of that extra bedroom,
buy better windows. High ceilings create spaciousness. Focus on what is most important,
like low operating costs."
Certainly, the photovoltaic system helps.
The system contains 48, 175-watt panels that
generate 1,000 kilowatt hours each month.
Tied directly into the grid, the house sends
power into the grid during the day, then pulls
it back at night. To reduce power requirements,
they rely on natural lighting and low plug loads. For example, any instant-on appliances
are plugged into power strips that
are turned off until needed.
"The idea is that you can spend money
differently from conventional housing," Adamson
says, "and arrive at a better, more
healthy, more comfortable house. Low operating
costs are a joy, and that will affect the
home’s long-term market value."
When building a straw bale house, there are a few things that really matter, and moisture is one of the most important. Straw readily absorbs
water, and if it does, bad things happen. For that reason, when the bales arrive they must be kept absolutely dry. When building flashing and working with other water-proofing features, care
must be taken that water cannot drip into the
walls. And the plaster—both inside and out—
must be breathable to avoid condensation.
"If you use straw bales, you are generally committed to natural plasters," Adamson says.
"Plastering is a big job, and the exterior cannot
be done in the winter. Even snow on the bales
is something you have to avoid."
Group project. Once the framework was built and the bales were stacked, a small army of volunteers descended on the work site and began slinging mud. Step one was coating
the bales with a clay mixture that waterproofs
and provides a surface for the rough plaster to
stick to. Then came step two, which was mud
mayhem. Over about three weeks, Adamson
estimates that 100 volunteers showed up to
apply the clay/straw mixture to all walls, inside
and out. Step two creates a phenomenal
mess, but at completion the rough plaster takes on the look of a man-made masterpiece.
The third and final coating was professionally
applied, and it smoothed and leveled the
surface, while retaining the hand-built characteristics from the volunteers.
"The plastering was amazing," Adamson
says. "People just kept showing up, there
were friends of friends of friends, people I
didn’t even know. But that’s how this community
is. People are energetic and motivated and they love to learn about new things. The
whole green building movement has captured
a lot of people’s interests."
Overall, the completed house cost about
$180 per square foot, but that doesn’t account
for the volunteer labor or Adamson’s time.
The family’s living area is about 1,500 square
feet, but that does not include the “grandparents
suite” that can be rented out.
Now that the Adamsons have moved in, what’s it like to live in a super insulated house with walls that are literally three feet thick?
"It is so quiet throughout the house it takes some getting used to," Adamson says. "You can be inside shouting at someone on the deck, and they can’t hear you. And it’s the same inside. The walls are sound absorbing and it’s very, very quiet.
"The other thing is that we stayed so comfortable
in the summer, even without air conditioning.
After a year we’ll know more about
energy needs. If we have to add a small wood
stove for heat, we’ll do that. And if we aren’t
at net zero electrically, we can add a solar hot
water heater to help out. Overall, though, it’s
a privilege to live in such a wonderful house
made with natural products."
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