In discussing the maintenance of a good indoor environment, the authors advise that the direction of airflow can be more important than the rate of air flow. Any laboratory that uses chemicals or compressed gases requires a non-recirculating air supply system. This means that all of the air that comes into the room is used and then exhausted. The exhaust system must be controlled and coordinated with the supply air system to maintain the proper pressurization in each room in relation to the surrounding rooms. Care must be taken to choose the right external building exhaust and air intake location so as to avoid drawing exhaust effluent into the fresh air supply and contaminating the building. The height of the exhaust stack should extend 10 feet past the highest point on the roof, and the discharge velocity must be sufficient to safely dissipate the exhaust plume. The article also explains how facility design features can make facility maintenance easier. Design features that can facilitate maintenance are suggested. Suggestions are also outlined for saving energy, which not only reduces the operating expenditures but also has a positive impact on the environment. The concluding section of the article focuses on the testing of the design solution as an important aspect of the building process. This involves the development of a commissioning plan (validating the building systems and the facility design solution and the provision of occupant training), validation of individual components, and evaluation of the entire system.