What term is used for the three-dimensional volume of space enclosed by a form?

The term that refers to the three-dimensional volume of space enclosed by a form is "mass." In architectural terminology, mass describes the actual physical volume of an object, which is crucial for understanding how a structure occupies space within its environment. When architects design buildings, they consider the mass of the structure to create a sense of scale, proportion, and visual impact, as well as to define the spatial relationships within and around the building.

Mass can also play a role in regulating environmental factors, such as thermal comfort and energy efficiency, by absorbing and releasing heat. It is essential to differentiate mass from other terms like void, which refers to empty spaces, or space, which is a broader concept that can encompass various kinds of areas, both occupied and unoccupied. Structure refers more to the system of elements that supports a building, rather than the volume enclosed by it. Understanding mass is vital for creating effective architectural designs that engage with their surroundings and fulfill their intended purpose.