Do not force unlike buildings into one rate
A restored corner property, a narrow tenanted shop and a vacant building needing roof work should not be compared only by price per square foot. Note what is producing income now, what will require cash after completion and how easily the next owner could use it.
Use blanks as questions
If the present use, approved plans, tenancy or repair history is unknown, leave the field blank and ask for it. A clean-looking table should never hide missing information.
The useful result is not a winning column. It is a clear view of which building fits, which one carries hidden work and which questions remain unanswered. Keep those unknowns visible before deciding.