The traditional Thai house is ideally adapted to its environment. The open high-pitched roof facilitates air circulation. Open windows and walls in combination with a large central terrace provide ideal ventilation and offer relief from the hot and humid climate. Wide overhanging eaves protect the house from sun and rain. Rainwater runs off the steep roof quickly and falls through the permeable terrace and house floors. The use of wood and bamboo reflects the once abundant forests that provided these materials ubiquitously and cheaply. In the past, an agricultural society existed in relative harmony with its natural environment.
credit : http://www.orientalarchitecture.com/thailand/statewide/thaihousesa.php