THERE’S NO QUESTION that size-up is one of the most important functions that must happen on every fire. The first-due officer is usually the one tasked with conducting the initial size-up and formulating the initial incident action plan and, often, it is the first-due engine company’s officer giving the first-in report. A good size-up is concise, paints an accurate picture of the incident, identifies key hazards, and declares the initial strategy and tactical needs to other incoming companies.
Let’s face it, we all have folks who give a ridiculously long, drawn-out size-up, usually resulting in other companies tuning out halfway through their dialogue. We also know the folks who struggle to give a size-up and include little pertinent information. Therefore, it stands to reason we should practice size-up often to make sure we are relaying the most pertinent information in the shortest amount of time possible.
Layers of Size-Up
Preincident Knowledge
Size-up comes in phases. The first step is preincident knowledge. From preplans, district familiarization, time of day, weather, construction areas, school zones, and target hazard information, we can do much to enhance our operations and formulate plan “A” strategies and tactics by doing a little legwork before the bell sounds. Once the alarm is received, engine officers must take all known information into account and rapidly make decisions that will set the tone for the entire incident.
Dispatch Information
Next comes the information provided by dispatchers. Dispatch information may provide important information, such as known entrapment, where the caller reported that the fire started, etc. However, this information may be limited, incomplete, exaggerated (due to hysterical callers), understated (lack of real event knowledge by the caller), or even completely inaccurate. Responding companies must take this information with a grain of salt and maintain mental readiness to mitigate the actual incident found, not the one dispatched.
Windshield Report
Next is what most of us associate a traditional size-up with: the on-scene size-up report. This includes the “windshield report” given as the first-due company officer relays his observations noted on arrival (photo 1).
360° Size-Up
The second component of the on-scene size-up usually (hopefully!) involves a 360° size-up done by the first-arriving officer. As the officer dismounts the apparatus and takes a lap around the building, he must consider numerous factors nearly simultaneously to determine the appropriate tactical use of his crew. The officer should conduct a 360° size-up whenever possible to allow him to paint a better picture of the incident. A simple lap around the structure may reveal key time-sensitive information.
Building construction, location and extent of smoke and fire conditions found, civilian rescue, line placement and size, hazards (utilities, covered swimming pools, etc.), flow path, imminently threatened exposures, and incident needs from other arriving companies are just a few of the considerations the first-due engine officer must process as he takes his 360° lap around the building. The C-side view is extremely important in more completely identifying the fire conditions, potentially trapped victims, off-grade floors that may not be visible from the front of the building, and hazards. If the first-due engine officer cannot perform a 360° size-up (building size, pressing incident needs, etc.), this should be relayed via radio to incoming units and be assigned as soon as possible to a later-arriving company.
Construction
Building construction and size must be accounted for during the size-up process. Due to cocklofts, open stairwells, and wood interior structural members, fires in Type 3 ordinary construction buildings behave differently than Type 2 limited combustible construction buildings. Likewise, wood frame Type 5 (wood frame) apartments are drastically different from Type 1 (fire-resistive) apartments. Whereas the latter are usually relatively compartmentalized and can burn for long periods of time before collapse, the former have tremendous fuel potential from the contents and the building materials themselves.
Building Size/Orientation
The size of the building and its orientation also warrant consideration. Is it a 2,000-square-foot ranch style house or is it a 10,000-sq.-ft. “McMansion”? Will your preconnected hoselines reach the fire compartment or will extended stretch operations be needed? It takes more effort and time to perform the latter and may require the assistance of additional companies to make the advance successful.
Additionally, the first-arriving engine company must determine the structure’s setback from where the apparatus is positioned on scene. Long setbacks also require more time and work to get hoselines in service and must be accounted for during the size-up.
Building Height
You cannot discuss sizing up a building without also talking about the height of the building. Tall buildings are a challenge for several reasons. First, they may be out of reach of our aerial devices, thus impacting rescue decisions. Second, many of these buildings are equipped with standpipes, pressure restricting devices, pressure reducing valves, fire pumps, or elevators. First-arriving crews must determine whether to and how to use one or multiple systems during the incident. Finally, the reflex time to get the needed personnel and equipment into position to search multiple floors, extinguish the fire, and ventilate the building is often significant. The likelihood of encountering a larger fire than was first observed on arrival by the time resources are ready to begin fire attack is high.
Era/Method of Construction
Other tactical considerations pertain to the method of construction used. For example, houses built prior to the 1940s were predominantly built using balloon-frame construction techniques, whereas newer houses are usually of platform frame construction. A fire showing from the upper floor or roof of a balloon-frame house may very well have originated in the basement and spread rapidly to the top floor/roof due to continuous vertical openings from the bottom to the top of the structure. First-arriving engine companies must verify the method of construction and determine if there is a basement prior to making entry.
Occupancy
Occupancy should go together with building construction considerations during size-up. Occupancy is simply what the building is used for. NFPA 101, Life Safety Code, lists 15 occupancy classifications. However, for the sake of time and space, we will only examine three broad categories that we often lump these specific classifications into during our size-up: residential, commercial, and mixed use.
Residential
Residential occupancies should prompt a strong suspicion of rescue potential due to their very nature of housing people at all hours of the day. Single-family dwelling fires account for a large percentage of both fires and fire fatalities in the U.S. fire service. Thus, it stands to reason, first-due engine companies should look for indicators that may assist with locating trapped occupants during the size-up. Cars in the driveway or garage, lights on, time of day (normal sleeping hours), toys in the yard, lights on inside or outside, and signs of pets are all key considerations that heighten the likelihood of potential victims.
Multifamily dwellings often present numerous challenges for first-arriving companies, as the life hazard can be great and on numerous floors simultaneously. Furthermore, many of these types of buildings are Type 3 or Type 5 construction, allowing unchecked fire to spread via combustible void spaces. This can stretch even the best engine companies thin, as they must quickly determine where to place the first attack line and effect a rescue. The size-up must include determining where the first-arriving crew can do the most good for the incident and those most in need of rescue. Often, a properly selected and placed handline can save the most lives by confining and extinguishing the fire.
The presence of exterior stairs on large, traditionally single-family dwellings may indicate that the house has been subdivided into smaller living units/apartments. The access from one unit to another (i.e., upper vs. lower units) may be walled off so that engine crews may not be able to access one unit from the other. In other words, the engine company may not be able to access the upper units from the front door.
Commercial
Commercial buildings should prompt different strategic and tactical considerations than residential structures. For instance, the first hoselines stretched may be best served connecting to the fire department connection (FDC) and supplying water to the building’s sprinkler system. The sprinklers may control or even extinguish the fire altogether while crews are stretching and advancing hoselines, minimizing damage and saving the building’s owner money and time in getting repairs completed. The economic impact of saving a business cannot be overstated, as these businesses often provide services, tax revenue, and jobs to our communities. Here are important considerations:
- Commercial occupancies during business hours may have numerous life hazards, whereas in the middle of the night they may have no life hazards (other than our own) present. Additionally, a fire in a commercial business that is closed and sealed up with no fire showing on arrival may provide initial companies time, due to their ventilation-limited status, to secure a water supply, deploy hoselines, ladder the building for ventilation, and get sufficient resources in position to begin extinguishment efforts.
- While a fast attack off tank water may be sufficient to mount a fire attack and begin search and rescue at residential fires, commercial fires dictate securing an adequate water supply during the initial moments of the incident. Firefighters should ensure the correct attack lines are in position and properly staffed to the extent possible prior to forcing entry into these buildings, as fire conditions are likely to increase once larger commercial doors are opened for ingress/egress.
- One last consideration is whether and when to ventilate storefront windows. If possible, crews should not break them until crews can confine the fire with their attack lines. This fresh influx of oxygen may facilitate rapid deterioration of fire conditions prior to crews gaining control.
Furthermore, the type of occupancy can impact hoseline selection for fire attack. While smaller 1.75-inch attack lines may be chosen for fire attack in single-family or even multifamily dwellings, medium-diameter hoselines (2 inches, 2.25 inches, or 2.5 inches) are the normal, default, minimum handline size chosen for fire attack in commercial occupancies due to their large-capacity flows and superior knockdown power. Additionally, occupancies storing heavy fuel loads (furniture warehouses, tire stores, etc.) may warrant using large caliber streams in a transitional manner in the early stages of the incident to knock down heavy fire conditions. The rule of thumb of “big fire = big water” applies here. The “blitz attack” with large-caliber streams (deck guns, portable monitors, etc.) can rapidly knock down large bodies of fire, buying time for personnel stretching handlines for final extinguishment.
Mixed Use
Mixed use is exactly as the name implies. Historically, we think of the old taxpayers (commercial business on the first floor with living units on the upper floors) and the more modern strip shopping centers. These structures often contain numerous and variable-use businesses that may house very different life hazards, fire loads, and hazardous storage. They often have shared cockloft or attic and basement spaces and are usually built of Type 2 or Type 3 construction but sometimes even Type 5 construction.
There has been a resurgence in recent years of the taxpayer concept even in more affluent areas where there are restaurants, businesses, bars, etc. on the lower floors and apartments above. The threat to life is high in these buildings, as occupants may become trapped in the event of a fire in the commercial occupancy below. Engine officers must work quickly to identify if fire escapes are present and in working order, whether occupants are trapped at windows or on fire escapes, and where the interior access is for the upper floors (rear stairs, common stairs, elevators, etc.). A 360° size-up is critical in these situations and must be completed before deployment of resources.
On-Plane, Below, or Above?
One vitally important component of size-up is determining where the fire is located. We can accomplish this in several ways. First, we can visually see the fire. This, of course, is the easiest way to know where the fire is and requires less skill. However, we often see smoke only or extended fire, not necessarily the seat of the fire on arrival. Firefighters and officers must be careful not to misdiagnosis the situation.
That said, another fantastic approach to identifying the location of the fire is to read the smoke. Specifically, we are looking at volume, velocity, density, and color. There is a lot more that goes into reading smoke but overall the rule of thumb is that the heaviest, thickest, fastest moving, and darkest smoke is closest to the seat of the fire, while slower, lighter, thinner laminar smoke is farther away as it’s not as “heat driven.”
Finally, one way to quickly determine where the fire is located is to simply look at the flow path when we open our point of entry. If there is smoke issuing from the top of the door and fresh air being drawn at the bottom of the doorway (bidirectional flow), we have an “on-plane” fire, meaning the fire is on the same level as us. Conversely, if we open the door and it is all exhaust (unidirectional flow), we have an intake somewhere else in the building. In this scenario, the first-due engine officer must slow down a little and try to locate where that intake is. It may very well be a fire below us (think basement fire) or we may even have a wind-driven fire (pay attention to wind direction and velocity). Lastly, if we open the door and the door is all intake (gases being drawn in, up, and away), then the fire is likely above us (upper floor or attic fire).
Interior or Exterior Water First?
Where the fire is and how much fire is present often determine whether we go for the knockdown via interior attack from the get-go or consider exterior water first (transitional attack) or take a defensive posture. Is the fire an interior fire? Is it an exterior fire? Is it an interior fire that has extended to the exterior or to the interior? Is it a contents fire or has it extended to involve structural members? Are there conditions that are out of our normal (i.e., hoarding conditions, structural dilapidation, excessive fuel loading, hazardous materials, etc.)? Are there pressing exposure concerns? Furthermore, are there reports of victims trapped? Are there indicators that may amplify our suspicions of finding victims despite lack of reports (cars in the driveway, toys in the yard, time of day, etc.)? Answering these questions often shapes our initial strategic and tactical decisions.
In my experience, if you respond to an interior residential fire and the fire is located on the same level or above you, the default position should be initiating an interior fire attack (staffing and conditions permitting). Conversely, if I have an exterior fire that has extended to the interior, I have a fire below me in a basement, or I am met with atypical conditions (such as hoarding conditions), then I may decide to use exterior water first to take some energy out of the fire before entering the building (if possible) for final extinguishment.
Exterior fires that may spread to the interior or attic space of a residential fire should prompt consideration for exterior stream placement either before interior attack is commenced (transitional attack) or simultaneously while interior lines are being deployed. Examples of these “outside-in” fires include rear porches, exterior siding fires, balconies, decks, and landings. The officer may opt to apply water from the initial handline to control the exterior fire before entering the structure to check for extension and complete final extinguishment.
Another useful tactical consideration during the engine officer’s initial size-up is using one member of the company to place a second hoseline (either a handline or portable monitor, depending on the volume of fire) in service on the exterior fire while another firefighter simultaneously deploys another handline for interior attack to the entrance that has best tactical advantage.
Regardless, until a primary search has been completed, we must look for ways to effectand protect the search. We do this by establishing the attack corridor with our hose stream. This is often best done by placing our line between the fire and the searchers and victims inside the fire building and using our stream to cool, confine, and extinguish the fire. If extinguishment is not possible due to conditions, lack of personnel, etc., the line can often still be used to buy time for a rapid primary search of searchable spaces.
Wind Direction/Veiocity
This topic is one that we have no control over but can drastically influence fire behavior. If there is a noticeable wind on the rear of the structure and we enter through the front of said structure, an open or failing window or door may result in a wind-driven fire heading straight for the engine company’s position. This situation may warrant the engine company altering the initial plan of attack and relocating the hoseline to avoid being caught in the flow path of a wind-driven fire.
Time/Location
Other considerations that must be factored into our size-up are the time of day and the location of the incident. We briefly discussed this above but, simply put, residential fires should always prompt a suspicion of victims. This is especially true in the middle of the night when most people are sleeping. Data from the U.S. Fire Administration reveal that the highest percentage of fire fatalities in residential structures (49%) occurs between the hours of 11 p.m. and 8 a.m.
Additionally, is the fire in a neighborhood or in a commercial district? What’s the water supply like in that area? Is the fire in a district that has a history of hostility toward first responders? Responding units may be wise to request law enforcement for crowd control and scene security while en route. Is the fire in an apartment complex known to be already weakened by previous fire incidents in the building? Or perhaps the fire is in a building known to be under construction. These situations should cause first-arriving companies to consider collapse potential during their initial windshield size-up and 360° walk-around, as normal apparatus positioning and commitment of personnel may need to be altered.
Choosing the Correct Attack Package
The first-arriving engine company must choose the appropriate attack line/ nozzle for the firefight to be effective. Stretching short; having excessive hose on the ground resulting in extra weight, kinks, and twists; and not flowing the right amount of water in the right location will all negatively impact the outcome of the fire attack.
Pulling too small of a handline (i.e., 1.75-inch attack line on a large commercial building fire) can have disastrous outcomes, resulting in the crew being driven from the fire area or, worse, being caught underequipped in hostile fire conditions. Pulling too large of a handline for the situation may provide plenty of water but may also slow advancement, cause rapid fatigue of crew members, and have too much weight and nozzle reaction to allow members to “move and flow” when needed. Great engine companies choose the most effective tools for the respective job and use them with the expertise of true professionals.
Water Supply
Another tactical consideration that must be accounted for during both the travel to and size-up on the scene is water supply. The type and size of the building, its occupancy, conditions encountered, response times and types of later-arriving companies, availability and distance to an adequate water supply, and department standard operating procedures (SOPs) all influence the decision of when and how to secure water supply.
In the residential setting, it is common for the first-due engine company to proceed immediately to the scene and begin a fast attack with available tank water. Tank size comes into play, however. If the engine only has a 500-gallon onboard water tank and the second-due apparatus is more than five minutes away, it may be prudent for them to secure their own water supply if it’s within a reasonable distance. However, should there be confirmed entrapment of occupants, or the second-due engine is less than two minutes out, the first-arriving engine officer may opt for deferring water supply to the second-due engine company.
Another tactical consideration would be the use of booster backup. This tactic involves the second-due engine supplying their tank water to the first-due engine and deferring water supply to the third-due engine. The idea is to frontload initial water and staffing to expedite fire attack and primary search—the two most critical lifesaving tasks we perform on the fireground. However, this tactic is primarily advantageous in residential occupancies and should be discouraged in most commercial structure fire settings, as larger fire streams and the sheer size and fuel load of these buildings require larger volumes of water, greater complements of personnel, and increased ventilation and forcible entry.
In areas lacking hydrants, water supply may come in the form of relay pumping, drafting operations from dump tanks supplied via water shuttles, and nursing operations from tenders supplying the attack pumper. These operations often delay establishment of a sustainable water supply due to more extensive setup time, travel distances of the resources needed, and lack of sufficient personnel/equipment. These areas should be identified beforehand and the various water supply tactics drilled on and communicated clearly with all companies likely to be involved. This takes extensive training, assignment discipline, and coordination to be successful.
Auxiliary Systems
The presence of FDCs supplying sprinkler and standpipe systems, fire alarm systems, elevators, and special extinguishing systems (high-expansion foam, hood systems in restaurants, carbon dioxide or other inert gas extinguishing systems, smoke removal systems, etc.) should all be factored into the first- due officer’s size-up. In our response model, the second-due engine company is responsible for securing their own water supply and pumping the needed FDC. In other systems, the first-arriving engine company may be tasked with this assignment.
Access Issues
Another size-up consideration is access to the structure. Can units access all sides of the building? Is the building on a narrow, crowded roadway or on a broad, reasonably open street? Can needed resources, such as aerial ladders, rescuecompanies, etc., access the building as needed? Trees, power lines, parked cars, and landscaping features may all impact access to the building. Dead-end streets and cul-de-sacs also impact access, as potentially only one or two apparatus may fit close enough to the structure to be effective. Are there private bridges or low overhangs in your area? Can your apparatus safely cross them or fit underneath them during response? Identify these areas before an incident occurs.
Finally, is overcrowding an issue? Cars may be illegally parked, blocking fire lanes, normal access, and hydrants. This can cause a delay in water supply; longer, more complicated hose stretches; and the inability of aerial apparatus to reach their target locations on the structure for rescue, ventilation, and more.
Resources
This article would be remiss if we didn’t discuss the impact resources (or lack thereof) have on the fireground. In many fire departments, staffing is minimal at best. Often, companies in career and volunteer firehouses alike struggle to get the NFPA 1710, Standard for the Organization and Deployment of Fire Suppression Operations, Emergency Medical Operations, and Special Operations to the Public by Career Fire Departments, and its companion standard, NFPA 1720, Standard for the Organization and Deployment of Fire Suppression Operations, Emergency Medical Operations, and Special Operations to the Public by Volunteer Fire Departments, minimum of four firefighters on a given fire company. This lack of staffing can drastically alter what can be accomplished—and when— on the fireground.
For example, if an engine company arrives with only two crew members, then performing a 360° size-up and placing a line in service from the exterior initially may be all that are possible based on experience of the crew members, department SOPs, and conditions found. If victims are believed or confirmed to be entrapped, the company may have to choose between rescue and suppression but realistically won’t be able to accomplish both simultaneously in most situations. Conversely, a well- staffed engine company with more resources arriving in close succession may be able to split their crew for fire attack and search at the outset of the fire.
Furthermore, the correct apparatus must be dispatched on the initial alarm to get proper resources on scene as quickly as possible. If an aerial device is needed for rescue at the incident but isn’t dispatched initially or is responding from a considerable distance away, piling six engine companies on scene doesn’t solve the problem. While there may be enough personnel, the right resources aren’t there, and successful rescue of a civilian or firefighter trapped beyond the reach of ground ladders may be jeopardized.
Another example would be not having enough mobile water tenders on scene to maintain the needed fireground flows due to lack of those resources on the initial dispatch or long travel distances. If the water needed is unavailable, full extinguishment may not be possible in the early stages of the incident.
Thus, resources play a critical part during the size-up as the officer formulates his initial strategy and chooses tactics to begin combating the fire.
Size-Up Is a Process
Always remember that size-up is a continual and ongoing process. It is multifaceted and requires constant attention to detail, preplanning, and awareness of the dynamic and ever-changing fireground conditions. Engine companies must put in the time to know their buildings, response districts, fire behavior, water supply, and attack packages if they are to correctly identify the fire problem and take the correct actions to mitigate it. Mission success hinges on accurate size-up both before and throughout the incident.
REFERENCES
“Civilian Fire Fatalities In Residential Buildings (2017-2019).” Topical Fire Report Series. U.S. Fire Administration, 1 Jun. 2021. bit.ly/3yMYtYx.
“The First 3000 Rescues.” Fire Fighter Rescue Survey, 1 Jan. 2023. bit.ly/3PFWnPk.
NICK PEPPARD Is a 19-year veteran of the fire service and a firefighter/ paramedic at the Oshkosh (WI) Fire Department. He has a bachelor’s degree in fire administration from Waldorf University and numerous certifications and has presented at both regional and national conferences. He is a published author, podcaster, and fire service instructor.
