Why is a 'size-up' performed at the door before committing interior crews?

• A. To determine the hazards and safest approach; plan for rescue.
• B. To identify the number of occupants.
• C. To estimate the building's age.
• D. To perform a random equipment check.

Answer: (B)

At the door, the priority is to quickly assess hazards and map out the safest way to enter and conduct a rescue. This immediate size-up looks at how the fire and building conditions will affect interior operations—smoke and heat levels, fire location and spread, potential structural stability, and the best entry and egress routes. That information guides the incident action plan, helping you decide whether interior crews can advance, what tools and PPE are needed, and how to coordinate ventilation, search, and rescue. Knowing how many occupants may be inside can influence urgency, but the crucial reason for the door-size-up is to identify hazards and choose a safe, effective approach for the interior operation.