Which of the following is NOT an indicator of an imminent building collapse?

The correct answer is based on the understanding of indicators that point to structural integrity issues in a building. Signs of building repair, sagging floors and roofs, and settling noises are all warning signs that can suggest the potential for imminent collapse. For example, sagging floors and roofs indicate that the weight distribution has shifted significantly, which can be detrimental to the structure. Similarly, settling noises often indicate movement within the building's foundation or framework, raising alarms about its stability.

On the other hand, higher British thermal unit (Btu) development typically relates to heat and energy, which does not directly correlate to the structural integrity of a building. While elevated temperatures might indicate a fire or other hazardous condition, they do not specifically serve as an indicator of imminent collapse. Therefore, this choice stands out as it does not pertain to the physical characteristics or behaviors of the building structure itself that would suggest an impending failure.