Garage Apartments in College Towns

I have considering building a upper and lower garage apartments on my property in Abilene Texas. We use the house for teaching as a business.  I have used AirBNB and VRBO before but more interested in mid term rental through furnished Finder. This is a property with no garage and zoned commercial. For cash flow and to increase the value of the property I am looking at the numbers now but not not sure if the ROI will work.  No real questions just would like any incite from people who have added value to property they already own.  Thanks