The recent economic growth in the Association of Southeast Asian Nations (ASEAN) region has driven the rapid increase of energy demand in the region. Energy demand in ASEAN has grown about 2.5 times since 1990 and is expected to triple by 2035. Therefore, ASEAN will need to apply the concept of a low-carbon city or eco town to curb increasing energy demand and to mitigate emissions of greenhouse gases. This is because both increasing energy demand and carbon dioxide emissions could threaten the sustainability of future energy supply and impact the environment, health, and tourism- i.e. the quality of life. Therefore, this eco town project study focuses on the introduction of current and future energy efficiency technologies on buildings and road transport as well as smart grid technologies. Such technologies can be applied to any town in an ASEAN country, such as the Temburong District in Brunei Darussalam.