Timber houses for flood areas
• The great floods of 1982 and 1983, which affected the entire Parana - La Plata region of Paraguay, led to the development of prototype houses, designed to provide safe shelter, even if the floods submerged single storey houses, as they did in 1983.
• The design was jointly developed in 1983 by students of the Catholic University, Asuncion, and flood victims, under the guidance of Prof. Thomas Gieth, Centre for Appropriate Technology, Asuncion, and Dr. Wolfgang Willkomm, University of Hanover, Federal Republic of Germany (Bibl. 24.06, 24.17).
• The design criteria were: protection and escape from floods, low building costs, use of local materials and techniques, suitability for self-help construction.
• The solution was a two-storeyed house with an external stairway and platform around the upper floor. During floods the dwellers can take refuge on top, and planks can be laid between neighbouring houses to serve as bridges, where boats are not available. Local caranday palm logs were used for the framework, wall cladding, windows, doors, and even roof (made by alternately laying hollowed out halved logs, like Spanish tiles).
• To overcome the foundation problems associated with this design, an alternative solution was worked out in 1984 by Behrend Hillrichs, architectural student at the University of Hanover (Bibl. 24.08), suggesting houses that can float on the flood waters.
Normal position of houses on dry ground
Position of houses during flood: the poles keep them in a stable position.
View of houses from above: short bridges connect the platforms.
Normal raft-type platform
Advantages: simple construction; stable position during floods.
Problems: gradual wetting of floor; sinking of raft with increasing load of people and belongings and with gradual water absorption; risk of pole buckling under lateral water pressure.
Platform on floats (eg empty oil barrels)
Advantages: platform raised above water level; high load-bearing capacity; no gradual sinking.
Problems: more complicated construction maintenance of good condition of floats (no holes!); instability during floods (tendency to "dance" on the waves).
[Ukrainian] [English] [Russian]