The design of plant and animal housing is complicated because many environmental factors affect the production and well-being of living organisms. The financial constraint that equipment must repay costs through improved economic productivity must be considered by the designer. The engineer must balance costs of modifying the environment against economic losses of a plant or animal in a less-than-ideal environment. Thus, design of plant and animal housing is affected by (1) economics, (2) concern for both workers and the care and well-being of animals, and (3) regulations on pollution, sanitation, and health assurance. DESIGN FOR ANIMAL ENVIRONMENTS Cooling and Heating Ventilation Ventilation Management Recommended Practices by Species DESIGN FOR PLANT FACILITIES Greenhouses Plant Growth Environmental Facilities Other Plant Environmental Facilities