What structural element primarily supports vertical loads in buildings?

Columns are essential structural components in buildings, primarily tasked with supporting vertical loads. They transfer the weight of the structure above down to the foundation, ensuring stability and integrity. When a building's design includes multiple floors or significant roof structures, columns become crucial in distributing and managing these loads, allowing for safe and effective construction.

While beams and joists also play vital roles in the framework, their functions differ slightly. Beams are horizontal elements that primarily support loads transferred from joists and other parts of the structure, while joists act as horizontal supports for floors and ceilings, spanning between beams or walls. Ducts, on the other hand, are mechanical elements used for air distribution, and do not contribute to the structural support of a building. Thus, in the context of identifying the primary structural element that supports vertical loads, columns are indeed the correct answer.