There is no square foot rate for property for residential property. The value per square foot is merely a factor to consider when buying a home.
However the value per square foot for a particular property is affected by many factors.
For example just some of the factors that influence value of the square footage in a home varies with the quality of construction, the quality of the finish work, the location of the property and whether or not the property is an overimprovement for the area, just to name a few of the factors that influence the value per square foot.
Also, becaue the value of the land is often very large in San Jose, it is first important to subtract the value of the land before you attempt to calculate the value per square foot.
For example a home on a 6,000 square foot lot will sell for much less than the same home on a 1 acre lot.
If you were to divide the square footage of the house into the sale price to determine the number of dollars per square foot, you will get two different answers for the same house if you do not subtract the value of the land first.
For residential property I recommend that you do not rely on dollars per square foot as a reliable measure of Fair Market Value. .