In a building, the term 'live load' refers to:

The concept of 'live load' in the context of building refers specifically to the loads that are not permanently applied to the structure and can change over time. This is primarily associated with the weight of movable objects, such as people, furniture, and equipment, which can vary based on occupancy and usage of the building.

Live loads are crucial in structural design as they help engineers determine how much weight a building can safely support without compromising its integrity. These loads can change frequently – for example, a room may be fully occupied at one time and nearly empty at another, leading to fluctuations in the live load. This consideration is essential for ensuring safety and stability in various scenarios.

In contrast, other options refer to static or fixed loads. The weight of building materials and structural supports are considered dead loads, which remain constant. Earthquake effects are categorized under dynamic loads but are not regular live loads associated with the typical usage of the building. Understanding these distinctions is key for any contractor involved in building design and compliance with structural codes.