Unfortunately, it is much more complex than that.
Typically, appraisers are going to look for comparable homes within a target area of the home that you getting appraised - homes with similar features. As I'm sure you're aware, it isn't all to often that you find identical homes, and this is where the appraiser's expertise comes in.
They make adjustments to the value of the property based on their
expert opinion. For example, if the home you want appraised is 1500 square feet, and a home that they found near it that sold recently is 1600 square feet, they will take a variety of factors into account when they decide how much that the other home should be adjusted. Depending on the area you are looking in, that could be a nominal adjustment, or in some areas, that could be tens of thousands of dollars - it all depends on the appraiser's opinion of the value of your home vs. the comparables.
Although you outlined general guidelines, each home is different - as are the lenders that will be looking for appraisals. It also depends on the area you are looking to purchase in - it would be extraordinarily difficult to find several comparable homes meeting 1 mile radius, or even 1 year since the last time it sold date, if you were to look for a property in a rural area.
On the flip side, if you are purchasing a home within a large tract of new homes, a 1 mile radius may seem far to large to have a true appraisal.
I hope this didn't just confuse you more - if you have any more questions, just ask
