The following is an example of functional obsolescence?

• A. Old plumbing
• B. Cosmetic paint
• C. Updated roofing
• D. Outdated plumbing

Answer: (D)

Functional obsolescence occurs when a property's features become less useful or desirable because they no longer meet current standards or market preferences, even though the system itself may still work. Outdated plumbing fits this idea well: older pipes and fixtures may be unreliable, harder to repair, or not up to modern codes, reducing overall usefulness and desirability of the home. Cosmetic paint is purely cosmetic and doesn’t affect how the home functions. An updated roof enhances performance and value, not obsolescence. Old plumbing can be a sign of deterioration, but the concept most clearly illustrated here is the mismatch with current standards, which is why outdated plumbing is the best example.