There are many reasons people need a home appraisal other than a home loan. One reason is for an Estate. As in the TV show "Bless this Mess," where a couple inherits a dilapidated old farmhouse.
When someone inherits a house, there is usually no tax owed from the deceased's date. But from that time forward, taxes are typically owed after the deceased's date if the house increases in value. Tax professionals call this the home "basis." I have been called to appraise houses after many years have passed since the deceased's date to establish that "basis." Sometimes I have to go back over 20 years to establish the basis for a house.
A drive-by appraisal is usually done if the house has since been sold.
First, I try to find out what the house was like 5 years ago. I might find that from an old MLS picture, but usually, the owners describe the property.
After understanding the historical condition of the house, it is compared to the most similar sales like that description and sold 5 years ago. In addition, the real estate MLS service often has interior sales pictures, which can be compared to the subject's report.
At that point, I compare the "5 years ago sales" to the subject and complete the report. To not confuse a reader of that report, I use the "Extraordinary Assumption. This Extraordinary Assumption says the reader: "There was information given to me I must assume was accurate."
I also add, "If the terms of these extraordinary assumptions are not met, it could affect the value conclusions." In other words, if the information given to me about the house was wrong, the value conclusion might also be wrong.
I then reconcile the data from 5 years ago and explain how I determined the value for the subject.
Also, the report should state that the analysis is "As Of" a particular date.
There are many other considerations, like were values increasing or decreasing in that area then? But these are my basic procedures for an estate appraisal.