How Good Is Your Size Up?

PREPARATION:MOTIVATION: The size up of a structure fire by the initial arriving officer sets the tone for the eventual outcome of the incident. Being able to read what has happened and what will happen after arrival affects the deployment of resources and...

    g. 7,500 cubic feet times 37 BTU’s produces 277,500 BTU’s

    h. To raise the temperature of 1 pound of water 1oF requires one BTU

    i. If one pound of water at 62oF is raised to 212oF liquid, 150 BTU’s would be required

    j. When one pound of water at 212oF is converted to steam, an additional 970 BTU’s are absorbed

    k. The total number of BTU’s absorbed in converting one pound of water at 62oF to steam is 1,120


     l. Water weighs 8.33 pounds per gallon

    m. One gallon of water, when converted to steam, will absorb 9,330 BTU’s (8.33 times 1,120)

    n. If the area produces 277,500 BTU’s and each gallon of water absorbs 9,330 BTU’s when

        converted to steam, 30 gallons of water would be required to control the fire (277,500 divided by


    o. The water should be applied in no longer than 30 seconds

    p. Flow rate would be 60 gallons per minute

    q. A safety factor of 25% should be considered making to total flow rate 75 gallons per minute (60

        times .25 = 15 plus 60)

    r. Shortcut method is cubic feet divided by 100

  6. Resource requirements

    a. Engines (pumping capacity, water, or fire fighting equipment)

    b. Support units (trucks, squads, others

    c. Tankers

    d. Emergency medical service

    e. Command staff

    f. Rehab

    g. Specialty units

    h. Personnel

    i. Contingency planning (personnel and apparatus uncommitted and available if needed)



  1. Rescue

    a. Those in immediate danger

    b. Those near the danger area

    c. Others

  2. Exposures

    a. Other parts of the structure

    b. Other structures

    c. Livestock and other property

    d. Environment

  3. Confinement - number, size, and placement of lines

  4. Extinguishment – number, size, and placement of lines

  5. Overhaul

  6. Ventilation

    a. When – immediately for rescue or delayed until fire attack is ready

    b. Where – vertical or horizontal

    c. How – positive pressure, negative pressure, natural, hydraulic)

    d. Coordination with fire attack

  7. Salvage

  8. Acronym – RECEO VS



  1. Condition of structure – offensive or defensive operation

  2. Risk versus benefit

    a. Risk a lot to save a lot

    b. Risk little to save little

    c. Risk nothing to save nothing)

  3. Expected outcome – can the structure be saved




* Pre-arrival Information

* Structure Involved

* Fire Conditions

* Scene Priorities

* Risk Assessment


REMOTIVATION: Size up is a combination of available information, experience, and knowledge that result in formulating certain decisions on the emergency scene. Quick decisions based on the size up can impact the outcome of the incident.