FW: [Strawbale] CO2 production for building a house
Rob Gort, Bouwcarrousel BV
r.gort at bouwcarrousel...
Wed Dec 28 19:25:55 CET 2005
Hi Sven / Valentina
I'm Rob from Holland. I haven't got exact figures either and am quite
interested to in this subject. I did some LCA-work for the government in
the past. I just know, of a dutch company which fabricates adobe-like
stones with machines (named Oskam), that the production of these stones
uses only 1 % of the normal energy consumption which is needed to
produce comparable stones. Because straw bales are a less industrial
product then prefabricated adobe stones, their energy efficiency 'll
probably be even better. Off course, building with baked stones is a
typical Dutch and English tradition, in most other countries other
materials like concrete or wood are used more (the differences in
eco-profile between wood (esp. FSC-wood) and strawbales will be far
less)... The step between the eco-score of materials themselves and a
whole house is not just extrapolation. Stones or straw bales are only
part of the materials which are used in building, but normally the
construction takes about 80 till 90 % of the total weight of a building
(this is including the roof and floors). The lifetime and the
maintenance which has to be done, are also important factors. Comparison
between alternatives should be done in a honest way, so for a fixed
period of time like 100 years is a normal practice. Off course the need
for maintenance depends of the design of the building, so this is quite
difficult to estimate in standard figures.
About LCA further I can say the following. In LCA-terms, because you can
view the production of straw bales for building as nothing different
from a normal harvesting procedure, this step requires none extra
energy. So, in fact, the major factor is probably the extra transport
(in comparison with the normal transport to a fourrage dealer for
example)can be reckoned to be caused by the building process (off course
this could also be even less transport). When you adapt the straw bales
in size or shape and you use machinery like a cutter or sawing machine
for that, this should also taken into account. Plastering with clay 'll
have quite a positive effect, in comparison with using standard plasters
on basis of cement etc.
Valentine, when you have more information, please let me / us all