Earth-Sheltered Architecture is an architectural concept extensively used in traditional Persian architecture of hot arid climates. It is now gaining popularity as a means for energy saving in buildings. This paper explains diverse typologies of subterranean and semi-subterranean buildings. Key advantages of this construction include its energy efficiency, improved building protection, lower maintenance costs and increased privacy. Its main disadvantages include increased excavation and soil solidification costs, drainage and waterproofing problems, claustrophobic spaces and ventilation problems. By presenting scientific data and some case studies showing the impact of depth on the thermal stability of the subterranean spaces, recommendations are made for promotion of this architectural typology in contemporary Iranian situation.