This manual was prepared primarily for use in conducting a practical training course on the design of solar heating and cooling systems for residential and small office buildings, but may also be useful as a general reference text. Only active solar systems are described in this manual. Other books are available for passive designs. Liquid and air-heating solar systems for combined space and service water heating or service water heating only are included in this manual. Furthermore, only systems with proven experience are discussed to any extent. This manual was developed by the staff of the Solar Energy Applications Laboratory and vocational education specialists at Colorado State University in cooperation with the NAHB Research Foundation. A national advisory committee selected from various sectors of the home-building industry, university sources, private practice, and government, was established to provide advice and general guidance.