You can also double hack these if you have enough units and live in one unit and use one unit for your business, but of course that decreases your cash flow but increases your usability.You can also use an FHA loan to get a mixed-use property with only 3.5% down if the residential square footage if more than 50% of the total square footage.

Similar, there is rules for footage to count as living space.  

What would your thoughts be on adding a bedroom and bathroom to this floorplan without expanding square footage?  

We are in the woods where we really wanted to create another sort of living space outside of the square footage of the home. 

Not calculating maintenance expense could end up being a nightmare.I always estimate (using either the 50%, 1% or square footage rule) the annual maintenance / first year of maintenance fees for a ALL rental property.

I started out with value add, where we force appreciated properties by adding square footage and beds/baths.

After some investments in amenities (primarily hot tubs), our last 3 months have averaged 12k/m.This property is owned outright, and due to the size of the property, the small square footage of the units, and the lack of comps in the area we have found it difficult to lock down any refinancing.

Computers can analyze property based on subjective data (square footage, # of beds/baths, etc.) but cannot calculate for objective data (quality of kitchen cabinets/counters, size of bedrooms and bathrooms, view out the living room window, etc.).You should study the market yourself.

There are also discrepancies due to whether or not the public record includes garage square footage.

Most hit all the bullet points excepting:Spending $175 on renovation and adding square footage or unit count does NOT miraculously convert to valuation.