Building with Earth: Design and Technology of a Sustainable Architecture

resemble skyscrapers, and date from the
15th century (6.2).
In Scandinavia and in England, building with
sod was common in the 17th and 18th cen-
turies. These houses were constructed of
blocks cut from the top layer of loamy soil
together with the grass growing on it. The
blocks were inverted and used as bricks to
form walls without mortar. European immi-
grants brought this technique to the USA,
where a large number of sod houses were
built in the 18th and 19th centuries (6.4).
Some settlers also adapted the same idea
from North American Indian nations such
as the Omaha and Pawnee, who for cen-
turies had used the method to cover their
round huts with sod (Houben, Guillaud,
1984).
In New Mexico, silty soil blocks cut from
riverbeds, and containing a network of roots
which act as reinforcement, were used
for building walls. These blocks are called
terronis or terrones, and were sometimes
used in Mexico and Central America as well.
It is interesting to note that building codes
in New Mexico still permit building with
terronis.
In Germany, earth block work was used
in the 6th century BC; adobe blocks
40 x 40 cm and 6 to 8 cm high were used
in the fort of Heuneburg near Lake Con-
stance (Dehn, 1957). Around 140,000 blocks
and 400 m^3 of mortar were used to con-
struct its 3-m-high walls (Güntzel, 1986,
p. 23). An official circular introducing the
use of adobes in walls was published in

1764 (Güntzel, 1986, p. 23). David Gilly pub-

lished manuals on adobe construction in

1787 and 1790.

Production of earth blocks

Adobes are made either by filling moulds

with a pasty loam mixture or by throwing

moist lumps of earth into them. Different

types of moulds can be used; some of

these are shown in 6.5. They are usually

made from timber. The throwing technique

is commonly used in all developing coun-

tries (6.7, 6.8and 6.9). Here, a sandy loam is

mixed with water, and cut straw is usually

added and the whole formed into a paste

that is thrown into wooden moulds. The

greater the force with which the loam is

thrown, the better its compaction and dry

strength. The surface is smoothed either by

hand or by a timber piece, trowel or wire

(6.6).

One person can produce about 300 blocks

per day (including preparation of mix, trans-

62 Working with earthen blocks

6.3Traditional earth

dwellings of the

Pueblo Indians, Taos,

New Mexico, USA

6.4Sod house, USA

6.5Moulds for

adobes

6.6Removal of sur-

plus loam with a wire

6.3

6.6

6.5

6.4