Which aspect of building design is crucial for maintaining good indoor air quality?

Maintaining good indoor air quality is heavily reliant on proper ventilation systems within a building. Proper ventilation helps to regulate the exchange of indoor air with outdoor air, thereby controlling humidity levels and reducing the concentration of indoor pollutants such as volatile organic compounds (VOCs), allergens, and other harmful particles. It ensures that fresh air circulates throughout indoor spaces and provides a path for the removal of stale air.

While factors like cost of materials, color schemes, and window placement can influence other aspects of a building's design, they do not directly address the primary concerns related to air quality. For instance, even the most aesthetic or cost-effective materials can off-gas harmful chemicals if not adequately ventilated. Similarly, although the orientation and presence of windows can contribute to natural light and some passive ventilation, they cannot replace the need for a designed ventilation system that consistently delivers clean air throughout the building. Therefore, proper ventilation systems are a foundation of good indoor air quality practices.