Which of these would be considered functional obsolescence?

Functional obsolescence refers to the loss of value in a property due to outdated features or design flaws that lessen its utility or desirability in the current market. A bedroom-through-bedroom floor plan is often viewed as an example of functional obsolescence because it typically lacks privacy, can be seen as awkward, and may not meet the expectations of modern homebuyers. In contemporary home design, having a more open layout or clearly defined, private bedrooms is preferred. Therefore, the bedroom-through-bedroom layout may be considered less functional or desirable, contributing to a decrease in the home's market value.

The other options, while they represent issues impacting the property's value, do not fit within the scope of functional obsolescence. For instance, a home facing a busy highway might be more about location-related factors rather than an inherent design flaw. A home with a broken furnace would likely fall under physical depreciation or deferred maintenance rather than functional obsolescence, as this is a repairable issue. Similarly, severe structural damage to the foundation is a significant physical problem that would affect safety and livability, rather than an issue of outdated design or functionality.