Which condition must be met to be eligible for flood insurance?

To be eligible for flood insurance under the National Flood Insurance Program (NFIP), a property must meet specific eligibility criteria related to its construction. One of these criteria is that the property should have two solid walls and a roof, which ensures that it is structurally sound and capable of being fortified against flood damage to some extent. This design helps to define what constitutes a building in the context of flood insurance, as it indicates a level of permanence and attachment to the ground, which is vital in assessing the risk of flood loss.

In contrast, the other options present structures that do not meet the NFIP's eligibility requirements. A house on stilts may be elevated but does not inherently meet the classification of an insurable building under the NFIP. A building entirely over water typically does not qualify since insurable structures must be anchored on land. Lastly, a basement structure does not by itself indicate a habitable dwelling and may not fulfill the necessary criteria for flood insurance, as it might be subject to flooding in specific risk zones. Understanding these eligibility conditions helps clarify why structural integrity and design are crucial in qualifying for flood insurance.