Up to to units can be added no more than 1200 sq ft or 50% of the primary. 

I currently have a tenant paying $1100 a month, so the cashflow would just be added onto the principal to pay off quicker.

Value add: Rents below market $75-100, Rubs will be added, professional management shared with other property in the area for efficiency.

@Douglas Spence Yes 100% I stumbled across that option a few months back and am currently reaching out to companies so they can be added to the Skillbridge registry and I can go work for them.

This would be added to my portfolio.  

@Bryan Hurley, I think one of the hardest things to measure is how much value will be added by doing improvements on a property that is already in good condition.

Will be adding value through upgrades.

Will be adding value through upgrades.

There was value to be added with this place in some different ways.

Any expenses you incurred to obtain the property can be added to basis- mileage driven, inspection fees ect Make sure your tax pro has the date the properties were available for rent (not specifically rented) And make sure they have a good break out of any renovations done so they can capitalize what's required and expense what they can.