This publication provides a discussion of various energy conserving building systems and design alternatives. The information presented here covers alternative space and water heating systems, and energy conserving building designs incorporating these systems and other energy conserving techniques. Besides water, wind, solar, and bio conversion energy systems and building designs, natural cooling and ventilation, regional and site adaptation, and energy conservation considerations are also discussed. Diagrams are provided of the building designs, alternative energy systems, etc. The discussion includes: (1) calculating heat and cooling loads; (2) thermal performance of buildings; (3) division of interior space; (4) different types of water wheels and their operation; (5) components of a wind-generated power plant; (6) solar energy subsystem integration for home space heating; (7) low technology applications of solar energy; (8) anaerobic digestion for methane gas; and (9) fuel cell utilization. References are given with each chapter. This publication could serve as a reference for anyone who is interested in saving energy costs in their home, school, or other buildings. (MR)