During VEIS, what is the preferred method of assessment before entrance?

During Vent Enter Isolate Search (VEIS), visually inspecting from the outside is the preferred method of assessment before entry because it allows firefighters to gather crucial information regarding the conditions inside the building. This method helps to identify factors such as smoke conditions, flames, or any potential hazards that might pose a risk to the firefighters during the search and rescue operation.

By looking through windows and assessing the exterior, firefighters can determine if there are any signs of victims inside or if other firefighters are already on scene attempting a rescue. This visual assessment can also reveal the extent of the fire, allowing for better planning of the best entry point and tactics to use once inside.

Listening for movement inside can provide some insight but may not offer a comprehensive understanding of the situation. Knocking on the door could alert any occupants or potential victims inside but doesn't provide critical visual information. Signaling other firefighters is important for communication, but it does not contribute to assessing the interior conditions effectively before entry.

Thus, the visual inspection from the outside is integral for ensuring the safety of the firefighters and maximizing the effectiveness of the search and rescue effort.