What factors are considered in a primary size-up?

• A. Occupancy type, construction, location and extent of fire, life hazards, exposures, water supply, and weather.
• B. Color of exterior paint, roof age, number of windows, and occupant income.
• C. Fire origin, cause, and time of day.
• D. Equipment brand, shift length, and weather forecast.

Answer: (D)

During a primary size-up, you rapidly gather the critical factors that drive your first actions at the scene. This includes identifying the occupancy type to understand potential occupants and interior layout, the building construction and its condition to gauge collapse risks and fire behavior, and the location and extent of the fire to know where it started and how far it has spread. You also assess life hazards to prioritize rescues, exposures to protect adjacent structures, the water supply available to sustain an attack, and weather conditions that can influence fire growth and ventilation needs. These elements together guide immediate decisions about entry, hose line size and placement, search priorities, and resource needs. Details like exterior paint color, roof age, or occupant income don’t affect these immediate choices, and while fire origin or cause and the time of day matter for later investigation, they don’t drive the initial size-up decisions.