Thermal Assessment of Traditional, Partially Subterranean Dwellings in Coastal and Mountainous Regions in the Mediterranean Climate. The Case of Cyprus

Fully, or partially, subterranean dwellings have developed as a distinctive building type from the prehistoric to pre-industrial era in the Mediterranean region, often serving specific purposes. The energy benefits of such spaces are well documented mainly through the investigation of numerous examples found in vernacular architecture. Despite their environmental potentials, subterranean structures remain limited in contemporary design practices. The present paper reports on the findings of a systematic research that examines partially subterranean traditional dwellings in the coastal and mountainous regions of Cyprus, an island in the Eastern Mediterranean. The study focuses on the environmental assessment of these spaces, through the monitoring of air temperature and relative humidity, and on a brief demonstration of various passive strategies for indoor microclimate improvements. Although these structures are not very common in the vernacular architecture of the island, their scientific examination produces useful knowledge in terms of energy savings. This can inform contemporary design applications and form a basis for the drafting of environmental refurbishment guidelines, applicable for this particular building typology. The research indicates favourable temperatures and significant cooling effects in partially subterranean spaces during the hot summer period, especially in mountainous regions. Temperatures in such spaces during the cold winter period are found to exhibit higher values compared to the temperatures of above-ground spaces, although they remain below comfort limits. High indoor humidity is found to be a major problem, in both the summer and winter period, in the coastal regions of the island. It is highlighted that, although partially subterranean spaces have many environmental benefits, as earth offers thermal insulation and heat storage, generalizations should be avoided since a number of varying parameters, such as the local climate, geology, natural ventilation conditions and building materials used, influence considerably their environmental performance