Which of the following is a consequence of higher occupancy levels in a building?

Increased occupancy levels in a building often lead to higher pollution concentrations. This is primarily due to the fact that more people generate more indoor pollutants through activities such as breathing, using personal care products, cooking, and generating additional heat and moisture. The more individuals in a confined space, the greater the demand placed on the building's ventilation systems. If these systems are not adequately designed or maintained to handle the increased load, the effective dilution of pollutants is reduced. This can lead to a buildup of volatile organic compounds (VOCs) and other contaminants in the air, negatively impacting indoor air quality.

The other choices involve aspects that typically do not align with higher occupancy. For example, increased occupancy usually results in higher energy consumption instead of lower, as more heating, cooling, and ventilation are required to maintain comfort levels. Additionally, air quality tends to be compromised with more people, rather than improved, and efficiency in heating is generally not enhanced under higher occupancy conditions without proper management of the ventilation and heating systems.