site adjustments

I noticed that a lot of appraisals that I have reviewed in my area (San Diego), the appraisers typically apply a $1-$3 adjustment per a square foot of land. The value of land is not $1 a square foot anywhere in San Diego. I am working on an appraisal over an acre and a reconciliation of the...

Can anyone recommend how to do a site adjustment. My mentor used appraised land value as an indicator to a site adjustment but I am having trouble determining how to actually make a site adjustment. Anything I can set up in Microsoft Excel works best for me. Also, as a newly certified appraiser...