Building is either the act of creating an object assembled from more than one element, or the object itself. A building is usually a human-created object composed of more than a single element, permanently fixed to the ground, that mediates one or more aspects of the environment.
Buildings may be as simple as a lone roof providing shelter from the rain for a single occupant, or as complex as a hospital regulating temperature, air flow, light, gas content, bacteria movement, particle flow, pressure, and people movement and activities.
The design construction and operation of buildings is as old as humankind. Architects today design most large-scale buildings in a team with a large number of specialized engineers. Small residential buildings do not usually involve extensive work by architects or engineers.
