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Chug, Andrew, everyone -<br>
<br>
The figure for embodied energy depends of course on what you include.
Would straw have been baled anyway? What distance are the bales being
transported?<br>
<br>
I addressed this issue in an approximate way (there is, I think, no
other way to address it...) in my PhD thesis last year. The relevant
text is below - I hope the formatting comes out OK... My own
calculations are for "typical" conditions in the southwest of England,
where I was living at the time. The actual local figures will depend
heavily on the haulage distance.<br>
<br>
atb,<br>
Mark<br>
<br>
<br>
<h3>2.1.2:<span style=""> </span>Low ecological impact:</h3>
<p class="MsoNormal">Straw is a natural agricultural waste material,
requiring no
industrial processing.<span style=""> </span>As all energy
and resource inputs into crop growth are aimed at maximising the yield
of the
grain, the energy and environmental costs associated with use of the
crop
stalks are minimal, consisting only of those resulting from baling and
transportation.<a style="" href="#_edn1" name="_ednref1" title=""><span
class="MsoEndnoteReference"><span style=""><!--[if !supportFootnotes]-->[i]<!--[endif]--></span></span></a><sup>,<a
style="" href="#_edn2" name="_ednref2" title=""><span
class="MsoEndnoteReference"><span style=""><!--[if !supportFootnotes]-->[ii]<!--[endif]--></span></span></a>,<a
style="" href="#_edn3" name="_ednref3" title=""><span
class="MsoEndnoteReference"><span style=""><!--[if !supportFootnotes]-->[iii]<!--[endif]--></span></span></a></sup></p>
<p class="MsoNormal">As the energy costs of baling would, in almost all
cases, be
incurred anyway, the embodied energy of straw used in building may
therefore
usually be assumed to equal that involved in haulage of the bales to
site.<span style=""> </span>For a typical 400-bale strawbale house
(approximately 150 m<sup>2</sup> wall area, compatible with a 100 m<sup>2</sup>
dwelling floor area) in Britain, this is unlikely to exceed 3.5GJ, or
about
250kg CO<sub>2</sub> emissions<a style="" href="#_edn4" name="_ednref4"
title=""><span class="MsoEndnoteReference"><span style=""><!--[if !supportFootnotes]-->[iv]<!--[endif]--></span></span></a>.<span
style=""> </span>This clearly represents a considerable
saving over traditional building materials such as brick, stone or
concrete,
and a smaller (but still significant) saving over “natural” materials
such as
timber or recycled products such as cellulose insulation.<span style="">
</span>[This claim, however, assumes that no re-baling
is required.<span style=""> </span>This is indeed the case
where adequate bales are available, but some builders have not always
found
this to be the case and have therefore re-baled on site<a style=""
href="#_edn5" name="_ednref5" title=""><span
class="MsoEndnoteReference"><span style=""><!--[if !supportFootnotes]-->[v]<!--[endif]--></span></span></a>.<span
style=""> </span>Even so, the energy consumption in baling is
low – approximately 0.34 GJ for 400 bales<a style="" href="#_edn6"
name="_ednref6" title=""><span class="MsoEndnoteReference"><span
style=""><!--[if !supportFootnotes]-->[vi]<!--[endif]--></span></span></a>,
corresponding to about 25kg CO<sub>2</sub> emissions.]</p>
<p class="MsoNormal">To put these figures into context, let us compare
the
approximate embodied energy values and carbon dioxide emissions
corresponding
to 3 different full wall assemblies of 150 m<sup>2</sup> area<a style=""
href="#_edn7" name="_ednref7" title=""><span
class="MsoEndnoteReference"><span style=""><!--[if !supportFootnotes]-->[vii]<!--[endif]--></span></span></a>
and similar insulation value.<span style=""> </span>The
results are given in table 2.1 overleaf.</p>
<p class="MsoNormal">While no serious attempt at precision is possible
at present
with this type of calculation, it is clear that, even under the worst
realistic
conditions, strawbale construction compares favourably on these
criteria with
the principal competing low-U-value wall designs.</p>
<p class="MsoNormal">At the end of the building process, in contrast to
much
modern practice, the majority of the building waste can be recycled or
used as
mulch, reducing the load on municipal landfill and incineration
facilities.</p>
<p class="MsoNormal">Edminster<a style="" href="#_edn8" name="_ednref8"
title=""><span class="MsoEndnoteReference"><span style=""><!--[if !supportFootnotes]-->[viii]<!--[endif]--></span></span></a>,
in commenting on the results of her thesis on this subject, notes
however, that
misleading “greenwash” exists in sections of the strawbale community as
elsewhere.<span style=""> </span>Largescale use of concrete
in foundations, steel in frames, and cement in plastering, combined
with large
building dimensions, can result in a structure just as resource-hungry
(in
terms of both materials and embodied energy) as any conventional
building.<span style=""> </span>At the same time, she notes the
potential of
the technology for minimal impact when thought through carefully.<span
style=""> </span>In an article for an audience mostly
composed of enthusiasts, she notes:</p>
<p class="MsoBlockText">The results of my research and analysis show a
startling
spectrum of environmental impact severity among approaches to designing
with
straw bales.<span style=""> </span>Examining only measurable
indices of impact – embodied energy, water consumption, and waste
potential –
ten- and hundred-fold degrees of impact can be identified between
different
design options.<span style=""> </span>In some cases the
impacts exceed those of conventional building systems.<span style=""> </span>It
thus became evident that the potential
for lessening environmental impacts through deliberate design choices
is
substantial.<a style="" href="#_edn9" name="_ednref9" title=""><span
class="MsoEndnoteReference"><span style=""><!--[if !supportFootnotes]-->[ix]<!--[endif]--></span></span></a></p>
<p class="MsoBlockText"
style="margin-bottom: 6pt; page-break-after: avoid;">Table
2.1:<span style=""> </span>Comparison of embodied energy in
different construction methods</p>
<table
style="border: medium none ; width: 354.4pt; margin-left: 12.5pt; border-collapse: collapse;"
border="1" cellpadding="0" cellspacing="0" width="473">
<tbody>
<tr>
<td
style="border: 0.5pt solid windowtext; padding: 0mm 5.4pt; width: 163pt;"
width="217">
<p class="MsoFooter"
style="margin-top: 0mm; text-align: center; line-height: normal;"
align="center"><span style="font-family: Tahoma;">construction<o:p></o:p></span></p>
</td>
<td
style="border-style: solid solid solid none; border-color: windowtext windowtext windowtext -moz-use-text-color; border-width: 0.5pt 0.5pt 0.5pt medium; padding: 0mm 5.4pt; width: 92.15pt;"
width="123">
<p class="MsoNormal"
style="margin-top: 0mm; text-align: center; line-height: normal;"
align="center"><span style="font-family: Tahoma;">embodied energy / GJ<o:p></o:p></span></p>
</td>
<td
style="border-style: solid solid solid none; border-color: windowtext windowtext windowtext -moz-use-text-color; border-width: 0.5pt 0.5pt 0.5pt medium; padding: 0mm 5.4pt; width: 99.25pt;"
width="132">
<p class="MsoNormal"
style="margin-top: 0mm; text-align: center; line-height: normal;"
align="center"><span style="font-family: Tahoma;">CO<sub>2</sub>
emissions resulting from construction / t<o:p></o:p></span></p>
</td>
</tr>
<tr>
<td
style="border-style: none solid solid; border-color: -moz-use-text-color windowtext windowtext; border-width: medium 0.5pt 0.5pt; padding: 0mm 5.4pt; width: 163pt;"
valign="top" width="217">
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left">clay- and lime-plastered strawbale wall:<span style=""> </span><span
style=""> </span>rebaling</p>
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left"><span style=""> </span>sand</p>
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left"><span style=""> </span>clay</p>
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left"><span style=""> </span>lime</p>
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left"><span style=""> </span>transport</p>
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left"><span style=""> </span><b>TOTAL<o:p></o:p></b></p>
</td>
<td
style="border-style: none solid solid none; border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-width: medium 0.5pt 0.5pt medium; padding: 0mm 5.4pt; width: 92.15pt;"
valign="top" width="123">
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;"><!--[if !supportEmptyParas]--> <!--[endif]--><o:p></o:p></p>
<p class="MsoFooter" style="margin-top: 0mm; line-height: normal;">0.35</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">1.0</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">0.15</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">6.0</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">3.5</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;"><b>11.0
GJ<o:p></o:p></b></p>
</td>
<td
style="border-style: none solid solid none; border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-width: medium 0.5pt 0.5pt medium; padding: 0mm 5.4pt; width: 99.25pt;"
valign="top" width="132">
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;"><!--[if !supportEmptyParas]--> <!--[endif]--><o:p></o:p></p>
<p class="MsoFooter" style="margin-top: 0mm; line-height: normal;">0.03</p>
<p class="MsoFooter" style="margin-top: 0mm; line-height: normal;">0.07</p>
<p class="MsoFooter" style="margin-top: 0mm; line-height: normal;">0.01</p>
<p class="MsoFooter" style="margin-top: 0mm; line-height: normal;">0.36</p>
<p class="MsoFooter" style="margin-top: 0mm; line-height: normal;">0.25</p>
<p class="MsoFooter" style="margin-top: 0mm; line-height: normal;"><b>0.72
t CO<sub>2</sub><o:p></o:p></b></p>
</td>
</tr>
<tr>
<td
style="border-style: none solid solid; border-color: -moz-use-text-color windowtext windowtext; border-width: medium 0.5pt 0.5pt; padding: 0mm 5.4pt; width: 163pt;"
valign="top" width="217">
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left">brick / lightweight concrete cavity wall:<span style="">
</span>brick</p>
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left"><span style=""> </span>cellulose
insul<sup>n</sup></p>
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left"><span style=""> </span>l/w
concrete</p>
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left"><span style=""> </span>plasterboard</p>
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left"><span style=""> </span>transport</p>
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left"><span style=""> </span><b>TOTAL<o:p></o:p></b></p>
</td>
<td
style="border-style: none solid solid none; border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-width: medium 0.5pt 0.5pt medium; padding: 0mm 5.4pt; width: 92.15pt;"
valign="top" width="123">
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;"><!--[if !supportEmptyParas]--> <!--[endif]--><o:p></o:p></p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">63.7</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">10.5</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">7.2</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">3.6</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">10.5</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;"><b>95.5<o:p></o:p></b></p>
</td>
<td
style="border-style: none solid solid none; border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-width: medium 0.5pt 0.5pt medium; padding: 0mm 5.4pt; width: 99.25pt;"
valign="top" width="132">
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;"><!--[if !supportEmptyParas]--> <!--[endif]--><o:p></o:p></p>
<p class="MsoFooter" style="margin-top: 0mm; line-height: normal;">13.38</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">1.60</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">2.30<a
style="" href="#_ftn1" name="_ftnref1" title=""><span
class="MsoFootnoteReference"><span style="font-family: Symbol;"><span
style="">*</span></span></span></a></p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">0.55</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">0.75</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;"><b>18.58
t CO<sub>2</sub></b></p>
</td>
</tr>
<tr>
<td
style="border-style: none solid solid; border-color: -moz-use-text-color windowtext windowtext; border-width: medium 0.5pt 0.5pt; padding: 0mm 5.4pt; width: 163pt;"
valign="top" width="217">
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left">timber panel system:</p>
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left"><span style=""> </span>timber</p>
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left"><span style=""> </span>cellulose
insul<sup>n</sup></p>
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left"><span style=""> </span>plasterboard</p>
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left"><span style=""> </span>transport</p>
<p class="MsoFooter"
style="margin-top: 0mm; text-align: left; line-height: normal;"
align="left"><span style=""> </span><b>TOTAL<o:p></o:p></b></p>
</td>
<td
style="border-style: none solid solid none; border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-width: medium 0.5pt 0.5pt medium; padding: 0mm 5.4pt; width: 92.15pt;"
valign="top" width="123">
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;"><!--[if !supportEmptyParas]--> <!--[endif]--><o:p></o:p></p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">2.4</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">12.5</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">3.6</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">7.5</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;"><b>26.0<o:p></o:p></b></p>
</td>
<td
style="border-style: none solid solid none; border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-width: medium 0.5pt 0.5pt medium; padding: 0mm 5.4pt; width: 99.25pt;"
valign="top" width="132">
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;"><!--[if !supportEmptyParas]--> <!--[endif]--><o:p></o:p></p>
<p class="MsoFooter" style="margin-top: 0mm; line-height: normal;">0.36</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">1.90</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">0.55</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;">0.54</p>
<p class="MsoNormal" style="margin-top: 0mm; line-height: normal;"><b>3.35</b>
<b>t CO<sub>2</sub></b></p>
</td>
</tr>
</tbody>
</table>
<p class="MsoNormal">Strawbale construction, therefore, provides an
opportunity
for unusually ecologically sound building, but does not guarantee it:<span
style=""> </span>a thorough environmental audit of the whole
process is still necessary if ecological excellence is to be achieved.</p>
<span
style="font-size: 11pt; font-family: "Book Antiqua"; letter-spacing: -0.5pt;"><br
style="page-break-before: always;" clear="all">
</span>
<p class="MsoNormal"><!--[if !supportEmptyParas]--> <!--[endif]--><o:p></o:p></p>
<div style=""><!--[if !supportFootnotes]--><br clear="all">
<hr align="left" size="1" width="33%">
<!--[endif]-->
<div style="" id="ftn1">
<p class="MsoFootnoteText"><a style="" href="#_ftnref1" name="_ftn1"
title=""><span class="MsoFootnoteReference"><span
style="font-family: Symbol;"><span style="">*</span></span></span></a>
includes
carbon dioxide emitted in cement production</p>
</div>
</div>
<div style=""><!--[if !supportEndnotes]--><br clear="all">
<hr align="left" size="1" width="33%">
<!--[endif]-->
<div style="" id="edn1">
<p class="MsoEndnoteText"><a style="" href="#_ednref1" name="_edn1"
title=""><span class="MsoEndnoteReference"><span style=""><!--[if !supportFootnotes]-->[i]<!--[endif]--></span></span></a>
<b>Edminster</b>
A V (1995), <b><i>Straw Bale Construction: Patterns for a Sustainable
System</i></b>,<span style=""> </span>Masters Thesis, Department of
Architecture,
University of California, Berkeley, CA, USA<span style="">
</span>(also available as:<span style=""> </span><b><i>Investigation
of Environmental Impacts: Strawbale Construction</i></b>,<span style="">
</span>design AVEnues, Pacifica, CA, USA)</p>
</div>
<div style="" id="edn2">
<p class="MsoEndnoteText"><a style="" href="#_ednref2" name="_edn2"
title=""><span class="MsoEndnoteReference"><span style=""><!--[if !supportFootnotes]-->[ii]<!--[endif]--></span></span></a>
<b>Hofmeister</b>
R (1994:winter), <b><i>Straw-Bale Construction: How Does it Stack Up?,</i></b>
The Last Straw, issue 5, Tucson, AZ, USA</p>
</div>
<div style="" id="edn3">
<p class="MsoEndnoteText"><a style="" href="#_ednref3" name="_edn3"
title=""><span class="MsoEndnoteReference"><span style=""><!--[if !supportFootnotes]-->[iii]<!--[endif]--></span></span></a>
<b>Pierquet</b>
P (1997:winter), <b><i>How Good?: Embodied Energy of Insulation
Materials,</i></b>
The Last Straw, issue 17, Tucson, AZ, USA</p>
</div>
<div style="" id="edn4">
<p class="MsoEndnoteText"><a style="" href="#_ednref4" name="_edn4"
title=""><span class="MsoEndnoteReference"><span style=""><!--[if !supportFootnotes]-->[iv]<!--[endif]--></span></span></a>
Calculations based on 2 trucks carrying 200 bales each, and each with a
60-mile
round trip</p>
</div>
<div style="" id="edn5">
<p class="MsoEndnoteText"><a style="" href="#_ednref5" name="_edn5"
title=""><span class="MsoEndnoteReference"><span style=""><!--[if !supportFootnotes]-->[v]<!--[endif]--></span></span></a>
<b>van der
Zoom</b> H (2004:06),<span style=""> </span>unscripted talk,
International Strawbale Building Conference, Kalø, Denmark</p>
</div>
<div style="" id="edn6">
<p class="MsoEndnoteText"><a style="" href="#_ednref6" name="_edn6"
title=""><span class="MsoEndnoteReference"><span style=""><!--[if !supportFootnotes]-->[vi]<!--[endif]--></span></span></a>
maximum
figure obtained from calculations based on (i) data provided on bale
manufacturers’ websites, and (ii) observation of baling on a field in
Carmarthenshire.</p>
</div>
<div style="" id="edn7">
<p class="MsoEndnoteText"><a style="" href="#_ednref7" name="_edn7"
title=""><span class="MsoEndnoteReference"><span style=""><!--[if !supportFootnotes]-->[vii]<!--[endif]--></span></span></a>
Calculations based on unit embodied energy costs from various sources
tabulated
in: <span style=""> </span>ed. <b>Thomas</b> R (1996), <b><i>Environmental
Design</i></b>, London:<span style=""> </span>E & F N
Spon</p>
</div>
<div style="" id="edn8">
<p class="MsoEndnoteText"><a style="" href="#_ednref8" name="_edn8"
title=""><span class="MsoEndnoteReference"><span style=""><!--[if !supportFootnotes]-->[viii]<!--[endif]--></span></span></a>
<b>Edminster</b>
A V, <i>op cit</i></p>
</div>
<div style="" id="edn9">
<p class="MsoEndnoteText"><a style="" href="#_ednref9" name="_edn9"
title=""><span class="MsoEndnoteReference"><span style=""><!--[if !supportFootnotes]-->[ix]<!--[endif]--></span></span></a>
<b>Edminster</b>
A V (1996:winter), <b><i>Strawbale Design: Towards an Ecological
Accounting</i></b>,<span style=""> </span>The Last Straw,<span
style=""> </span>Tucson, AZ, USA, issue 13</p>
</div>
</div>
<br>
<br>
<br>
<br>
<br>
Andrew Webb wrote:
<blockquote cite="mid44575719.8030809@thegreenwebb..." type="cite">Closely
related to the question is embodied energy, if that is a help to them.
Straw bale has 0.24 MJ/kg or 31 MJ/m3 according to
<a class="moz-txt-link-freetext" href="http://www.canadianarchitect.com/asf/perspectives_sustainibility/measures_of_sustainablity/measures_of_sustainablity_embodied.htm">http://www.canadianarchitect.com/asf/perspectives_sustainibility/measures_of_sustainablity/measures_of_sustainablity_embodied.htm</a>
<br>
<br>
-AW
<br>
<br>
<br>
Chug. wrote:
<br>
<blockquote type="cite">Greetings baleheads
<br>
<br>
I have been asked this question to which I don't know an
answer........any input appreciated.
<br>
<br>
bale on
<br>
Chug
<br>
<a class="moz-txt-link-abbreviated" href="mailto:chug@strawbale-building....uk">chug@strawbale-building....uk</a>
<br>
<a class="moz-txt-link-freetext" href="http://www.strawbale-building.co.uk/">http://www.strawbale-building.co.uk/</a>
<br>
.
<br>
Dear Sir/Madam,
<br>
<br>
I am conducting research on using straw bale insulation for an energy
<br>
efficient housing project. I was interested in finding out how much
carbon
<br>
dioxide is emitted from one pound of strawbale. This information seems
to be
<br>
hard to find since strawbale isn't as widely used as other building
<br>
materials. If you could forward any information, that would be
exteremely
<br>
helpful. Thank you for your attention.
<br>
</blockquote>
<br>
_______________________________________________
<br>
Strawbale mailing list
<br>
<a class="moz-txt-link-abbreviated" href="mailto:Strawbale@listserv....org">Strawbale@listserv....org</a>
<br>
<a class="moz-txt-link-freetext" href="http://listserv.repp.org/mailman/listinfo/strawbale">http://listserv.repp.org/mailman/listinfo/strawbale</a>
<br>
<br>
</blockquote>
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