Simple core arrangement – stairs "wrapping around" elevator shaft.

In architecture, a core is a vertical space used for circulation and services. It may also be referred to as a circulation core or service core. A core may include staircases, elevators, electrical cables, water pipes and risers.

A core allows people to move between the floors of a building, and distributes services efficiently to the floors. A core may also serve a key structural role in a building, helping support it.