What term describes a property feature that becomes undesirable due to age or lack of modern utility?

The term that aptly describes a property feature that becomes undesirable due to age or lack of modern utility is functional obsolescence. This concept refers to a decrease in a property's desirability or value because certain features or layouts no longer meet current standards or expectations. For instance, a home with outdated layouts, such as a lack of an open floor plan or insufficient bathroom facilities, may be considered functionally obsolete. This type of obsolescence results not from physical wear and tear but rather from changes in consumer preferences or advancements in design and technology.

For comparison, physical deterioration refers to the decline in physical condition caused by wear and tear over time, which makes a property less appealing but does not necessarily relate to its functionality. Economic obsolescence occurs when external factors, such as economic downturns or changes in the surrounding neighborhood, negatively impact property value. External obsolescence specifically relates to outside influences affecting a property's value rather than its features or layout. Thus, functional obsolescence is the correct choice for describing the specific undesirability stemming from outdated or impractical property characteristics.