Environmental Engineering Reference
In-Depth Information
Moreover, we simply do not know how many wooden houses, palisades, bridges,
ships, or heavy weapons were built by the traditional settled societies on four con-
tinents (Australian aborigines did no build any permanent wooden structures)
during some i ve millennia of their existence. As a result, we will never know how
much wood ended up in the buildings of ancient China's large rectilinear cities or
how much of it sank to the bottom of the ocean with the naval and merchant l eets
of great voyaging Atlantic powers. The best I can do is to offer some revealing partial
quantii cations. Matters improve greatly once we reach the nineteenth century.
Wood requirements for traditional housing spanned a large range of volumes and
weights even when the comparison is restricted to relatively simple but fairly com-
fortable structures whose ownership could be commonly afforded. At one end of
the spectrum would be
minka
, traditional Japanese rural and urban house built of
wood, bamboo, straw (for often heavy thatching), mud, and paper, whose ownership
became fairly widespread during the Tokugawa era (Morse 1886). At the other end
of the range would be a log-house (be it the old Scandinavian
stock hus
, the tradi-
tional Russian
izba
, or the log cabins of early American settlers), a relatively massive
structure with sizes ranging from a single room to large, multilevel designs.
Minka
(literally, people's houses)—with their simple post-and-beam construction,
with walls often made of clay or bamboo, with sliding doors and interior partitions
frequently made of paper, and in rural areas often with only earthen l oors—were
lightweight. A 100 m
2
minka
might need as little as 8 m
3
of pine, cedar, or cypress
wood for its posts, beams, roof, and l oors (Kawashima 1986). In contrast, even a
small log cabin made with logs 15 cm in diameter needed about 15 m
3
for its walls,
l oor, ceiling, and roof, and a single-story 100 m
2
log house (with 25-cm-diameter
logs for outside walls and with heavy wooden doors and partitions) would need
easily 100 m
3
of heavy logs. And large farmhouses in Germany or Switzerland
required commonly 1,000 m
3
of timber (Mitscherlich 1963). In some climates well-
built wooden houses were inhabited for centuries, in other regions they needed
frequent repairs and rebuilding, making any attempts to estimate cumulative wood
consumption in traditional housing even more difi cult.
But what can be done with a high degree of coni dence is to compare the demand
for construction wood with the demand for fuelwood. Even if we take the highly
wood-intensive and rather large traditional Swedish log house, whose construction
(including outbuildings) would need 100 m
3
, that mass would be quickly dwarfed
by the wood needed for its heating. Typical annual consumption of fuelwood in
Sweden of the early 1800s was nearly 5 m
3
per capita (Gales et al. 2005), so i ve
people inhabiting a house would need 20-25 m
3
a year, and in just 50 years heating
