Below-grade living is not new; prehistoric man instinctively sought out subterranean shelters for protection against his enemies and extreme environmental conditions. Historically, the designs of below-grade enclosures were determined by such factors as availability of building materials, climatic elements, defensive needs, ceremonial beliefs, and cultural concerns. Contemporary use of underground house components includes basements, cellars, and other similar spaces. In most cases, however, individuals occupying below-grade quarters have either had access to an above-grade structure or have considered such quarters as temporary. The notorious basement that is wet, cold, and without adequate lighting has given an undesirable image to below-grade living. But proper construction standards and methods can lead to comfortable and healthful below-grade living quarters.
University of Kentucky College of Agriculture Cooperative Extension Service, "Energy Fact Sheet: Design Considerations for Below-Grade Housing" (1979). Agricultural Engineering Energy Series. 24.