Energy-efficient windows are found in all types of dwellings throughout the United States. Firefighting tactics have been negatively impacted by these windows. Officers and firefighters must recognize the presence of these windows in their size-up. Visiting and inspecting new construction sites or areas where renovations are taking place can also assist in identifying these windows. Fire showing out a failed energy efficient window is indicative of high heat and fire in the advanced stage. These windows can cause extreme heat and a smoke condition to develop in the fire area and areas above. These conditions increase the potential for flashover and back draft.

Tip: When encountering these windows at fires, horizontal ventilation must be controlled. All members must recognize the negative conditions that could be created by uncontrolled horizontal ventilation. Uncontrolled horizontal ventilation can seriously jeopardize members operating inside the building. Vertical ventilation is also critical when encountering these windows. Due to the difficulty in venting these windows from the exterior, an adequate vent hole in the roof may be the only way to vent a top floor fire or fire in the cockloft or attic area. The operative words when dealing with these windows should be caution and safety.