Thailand was a net energy importing country since it began a new phase of coordinated eco-nomic development in 1964. In turning from an agro-based economy to an industrial-based one, there has been a rapid and constant increase of energy consumption in Thailand, the only exception being during an energy crisis between mid-1997 and 1999. The interest in energy conservation for commercial buildings arose after an oil price hike and an oil short-age. Thailand's policy measure on energy efficiency in buildings is constituted by the Ministe-rial Regulation issued under the Energy Conservation Promotion Act.