In evaluating a house that has an actual age of 15 years, the appraiser assigned it an age of only 10 years because of the home's excellent condition. this is an example of:

The correct answer is - Effective age.

Explanation:

In the framework of real estate, the term effective age correspond to the condition of the building, as opposed to its actual age. Here, the house is so well preserved due to good maintenance or other factors, that its effective age is five years shorter than it actual age.  

Similarly, people have a biological age which corresponds to the age of the organism rather than chronological age. Due to such factors as harmful lifestyle, biological age of a person can be significantly longer than his or her chronological age.