This book examines the concept of the geometry of a courtyard space as an environmentally appropriate design parameter for climatic improvements in different climates. It studies the environmental potential of courtyard forms for microclimatic improvements, with the aim of providing outdoor living and of improving visual and thermal conditions in the surrounding buildings. The book focuses on solar control and studies the geometrical design variables, which directly or indirectly affect the environmental performance of courtyard buildings. The thermal performance of the courtyard form was investigated with the ultimate objective of incorporating systematically the thermal aspect with other aspects of design. A variety of courtyard geometries, in plan, were considered in the book taking the cities of Kuala Lumpur, Cairo, Rome and Stockholm as empirical backgrounds representing the climatic regions of hot humid, hot dry, temperate and cold climates respectively. The book should be useful to architects, engineers and anyone else who is interested in courtyard building design, solar architecture and energy saving in buildings.