If a gas vent is too low, which structural element of a building might it violate?

When a gas vent is installed too low, it can potentially violate the eaves or parapets of a building's structure. Eaves are the parts of the roof that overhang the walls, and they play a crucial role in directing water away from the building. If a gas vent is positioned below the height of the eaves, there is a risk that exhaust gases could obstruct the eaves or lead to improper venting, which can create safety hazards, including the possibility of harmful gases entering living areas.

Additionally, having a vent too low can lead to moisture and debris collecting around the vent, affecting its function and potentially leading to blockages or backdraft issues. It's essential for gas vents to be properly situated in relation to eaves and parapets to ensure effective ventilation and compliance with building codes. The other structural elements mentioned, such as the foundation, roof structure, and secondary walls, do not directly correlate with the height requirements for gas vents in the same way that eaves or parapets do.