On higher end properties I use micro-ground porcelain tile that is nearly perfectly square, and set it with 1/16" grout lines.

If you have the comps, you always have a strong rebuttal which can’t be refuted.On the square footage issues- I had a similar issue recently with a foreclosure I bought.

You find the average cost per square foot of those properties, multiply it by the square foot of the subject property, then add/subtract for condition and other factors. 

You will likely find some more BP members in the colorado area now as far as your plan, a red flag i see is the basement rental.  

Some of these Indianapolis neighborhoods include Broad Ripple, Fountain Square, Greenwood Area, South Broad Ripple, Fishers, Castleton, and many more.

The $20 means $20 per square foot per year.  

A couple of red flags went off the more we talked.1.

So take that into consideration when you're looking into your options and the law/code.2) Look into:RVTiny homes (some could be below the square footage that comes under scrutiny)Tiny homes on wheels (like RV, but smaller, and less unsightly) - the wheels at least get you out of the building code issues.

Keep your financials clean and squared away at all times.

How many bedrooms and bathrooms does it have and what is the square footage?