Bills I can think of in this category: Mortgage Interest, Insurance, Utilities, ...Not accurate- You need to use square footage not bedroom numbers.

So for whatever reason, the sq footage of our bonus room isn't showing anywhere in any documentation of the house which is about 300 sq ft missing from our house so our house would be 1915 sq ft.

Also, even if you were able to fit in two ADU's (one as an ADU and the other as a recreational building aka "game room" / bar) you have to factor in allowed buildable square footage on the property.

RUBS if usually a percentage based on square footage and occupancy. 

Square footage?  

So look up the comps or have an agent look up the comps and figure out what the price per square foot of the comps are, and multiply that number by the square footage of the subject property. 

Hello Kaylan Haight in Tampa, you should learn how to do a Search with Zillow and start with Land, then Towhomes, Apartments, Houses to really see what the price of a lot is and add on the New Construction Cost of similar square footage.

Add square footage by finishing out an attic basement (if it makes sense), fix up the kitchen and bathroom in the unit you'll be living in, stuff like that.

Not counting architecture/permitting/engineering you can build an average new construction house here for around $105-$110 per foot (including basement square footage).

I remember when getting my real estate license I learned that typically comps shouldn't be older than a month or so, on special circumstances, 6 months max.Another thing I noticed was that there was no finished basement square footage included (which makes sense because the appraiser did not go inside the property).Last thing I noticed is that the appraiser took an average of almost 8% off the property values that she used as comps.