As hygiene is of paramount importance to manufacture food that is safe for consumption, both the equipment and the factory used for processing and handling food products must be designed and constructed according to sound hygienic design principles. Incorporation of hygienic design into a food facility can prevent development of pests and microbiological niches, avoid product contamination with chemicals and debris particles from both inside and outside the factory, and may facilitate cleaning and disinfection. A hazard analysis of the foods manufactured must be conducted prior to designing a food factory, more specifically to determine the required level of hygienic design including zoning requirements for the food factory. Strong foundations, supporting structures, walls, floors, and roofs are required to ensure structural integrity of the building envelope, allowing a maximum level of hygiene in all areas inside the factory. All entrances/exits into the plant and the plant layout must be designed to control and obtain a logical flow of personnel, raw and finished food products, air, process aids, waste, and utilities. Zoning and barrier control can offer additional protection to the food produced. By taking all these elements into consideration, it is possible to minimize contamination of food products. This chapter will provide those responsible for the construction of food factories with best hygienic design practice guidance to produce food products and especially the type of products that require high hygiene, for example, infant foods or ready-to-eat products.