Final answer:
A detached building is a structure isolated from others by fire walls and protected by fire doors designed to prevent the spread of fires and enhance building safety.
Step-by-step explanation:
The structure that stands alone or is cut off from adjoining structures by fire walls with all openings protected by approved fire doors is known as a detached building.
The design of such a structure is to prevent the spread of fire and allow occupants a safe means of egress in the event of an emergency. Fire walls are constructed to be fire-resistant, extend continuously from the foundation to or through the roof, and have a sufficient fire-resistance rating.
The concept originates from the necessity to improve building safety and integrity following significant losses due to fires in urban areas, which have informed modern building codes and fire regulations.