This Paper presents a thermal investigation of four traditional houses tested
experimentally under the effect of external climatic conditions of hot dry region in Egypt
(Toshky region). The external and internal walls of the test house were constructed from
local sandstone blocks with 50 cm thick. The ratio between the external openings and the
external walls surfaces areas is less than 10 % . The external wall is covered internally with
2-3 cm cement mortar plasters, while the internal walls covered with 2-3 cm cement plaster
from both sides. Volts and domes covered the roof of the test houses. The external surface
of the roof covered with 2-3 cm white cement mortar plaster.
Results demonstrated that the local building materials (sandstone) suppress the swing
of external outdoor air temperature and stabilize the indoor air temperature at average level
below the average of outdoor air temperature by about 2-3 OC during the hottest period. The
results also show that it is possible to maintain the indoor air temperature significantly
below the average of the outdoor air temperature by about 4-5 "C, when modem insulating
materials together with the local building materials are used. Besides, the use of passive
cooling systems (evaporative cooling) maintained the indoor climate in the thermal human
comfort zone.