Why might modern construction materials lead to fires lasting longer?

The choice that indicates energy-efficient designs as a reason for fires lasting longer is significant because modern construction often incorporates materials and techniques that are optimized for energy conservation. These designs may include insulation, tight seals, and advanced glazing that can lead to a structure being airtight. This can trap heat and smoke inside during a fire, which can heighten the intensity and duration of the fire.

Additionally, energy-efficient materials might have unique burn characteristics. For instance, some modern insulation materials can combine with the intensity of a fire and contribute to prolonged burning due to their chemical composition. This characteristic, combined with the design that focuses on minimizing heat loss, can ultimately lead to an environment where fires are both more intense and last longer.

Contextually, while the use of flammable materials could influence fire behavior, it does not encompass the broader implications of systematic design features aimed at energy efficiency. In contrast, a reduced water supply or higher ceiling heights may influence firefighting strategy but are not fundamentally related to the length of time a fire might last once it has begun. Hence, energy-efficient designs explicitly enhance the potential for fires to burn longer due to the way they are constructed and the materials chosen.