Emergency departments (EDs) are often crowded, noisy, and chaotic places with limited privacy. Significant safety risks exist when treating psychiatric patients in the ED. When designing space to care for psychiatric patients in the ED, it is essential to consider all building products and materials to ensure a safe environment. The specific design recommendations to consider are: floors, walls, ceiling, electrical, heating, ventilation and air conditioning (HVAC), water, sealants, windows, bathrooms, doors, furniture and decoration, communication systems and telephones, signage, fire alarms and sprinklers, noise reduction, and infection control. As self-injurious behaviors and violence in the ED remain a growing public health concern, the need to prevent and manage these concerns is apparent, but often limited by space. The physical construct of a properly designed emergency psychiatry service will accommodate the necessary environmental modifications allowing for a multidisciplinary staff to safely perform assessments in a timely and efficient manner.