What is one of the key guidelines for installing a low level vent in relation to building openings?

The primary guideline for installing a low-level vent in relation to building openings is to maintain a distance of at least 5 meters to any air inlet of the building. This requirement is crucial for ensuring that any potentially harmful gases or odors emitted from the drainage system do not infiltrate into the building through its ventilation systems. Keeping the vent at this specified distance helps to maintain the indoor air quality and complies with safety regulations that aim to protect occupants from exposure to sewer gases or other contaminants that may arise from the drainage system. This guideline is based on practical considerations of airflow and potential backflow from sewer systems into habitable spaces.

The other options, while they may pertain to other aspects of drainage installation or environmental considerations, do not directly correlate with the established guidelines for low-level vent positioning in relation to building openings, which is the focus of this question.