Designing Ecological Habitats - Gaia Education

green builDing in termperate climates 75
Canada, Australia, China, Mongolia
and most European count ries. It’s a
fast growing, very creative, and at the
same time constantly professionalizing
movement.
In the following, I try to sort the
characteristics of strawbale build ing
under the Four Dimensions of the
EDE curriculum, knowing that conscious
readers are aware of the fact
that many of the topics mentioned
also relate to other Dimensions than
the one in which they are listed.
Ecological Aspects
Renewable materials like strawbales and wood bind carbon dioxide during
their lifetime as growing crops and trees. Choosing these materials for
the construction of an environmentally-sound house means sequestering
carbon from the atmosphere into the fabric of the building for up to onehundred
or even two-hundred years. If the plants are grown according to
organic farming principles, as in combination with other crops, the emission
of other greenhouse gases like nitrous oxides can be avoided, and even
more carbon can be sequestered by building up new soil (keyword: ‘carbon
farming’). Making up the balance of CO2 emissions during production of
the insulating material including carbon incorporated in the material, the
use of strawbales instead of conventional mineral wool saves about 25 tons
of CO2 – which means that energy put into the manufacturing of the mineral
wool can be more sensibly applied to building a strawbale house and then
heating it for about ten to fifteen years.
Following the principles of passive solar design, and installing a
controlled ventilation system with heat recovery, it is possible to achieve
heating energy consumption of only 15 kWh/sq.m. This is more than
ten times lower than that of the average building in Northern and Central
Europe! The remaining amount of heat energy needed can be provided by
very modest systems using wood, biogas and/or solar power. If a higher
technical investment is possible, solar systems with seasonal solar storage
tanks, best in combination with a local heating grid, can be appropriate.
When plastered with clay or lime, strawbale walls can additionally reduce
the need for heating and cooling by moderating indoor temperatures during
changing weather conditions throughout the day and year.
In 2002 and in 2006, parts of Sieben Linden underwent carbon footprint
studies, carried out by the universities of Kassel and Berlin. 1 The studies
found that the emissions for housing were 90% lower than the German
average, including construction and heating. In the case of one strawbale
building built only by hand with natural and reused materials, the overall
A strawbale house at
Sieben Linden built
entirely by hand.