-While central AC may be important to some tenants, I think your main point of competition and what is likely more important to a potential renter are bigger things such as how many bedrooms, square footage, price, location, is it well maintained.

Square footage Lot size These are Mainly preferences I know but they help

They may not allow the square footage of the street surfaces to be included in the calculation, they may not allow set-backs to be used in the calculation and there may be requirements for open space.

When that is the case, do you go of the price of newer houses that are selling in the area with the same square footage?

After renos and based on comps in the neighborhood, we're projecting resale around $62-$63/ft.Square footage came in at 2,400 roughly.

But they also COULD show that the ratio starts decreasing (or increasing) with larger square footage.

You're not going to be able to analyze based on square footage or number of rooms.  

Where you are looking in Dublin (not sure if that is but that's what you mentioned), duplexes are going for over $200k and three units depend based on square footage.

HelloQuick scenario is I got an off market property large enough to subdivide square footage wise however the lot is odd shaped so when I split the lots to meet the minimum widths the one lot falls short approximately 800 square feet.

What's the square footage?