Then, add on the cost of New Construction to know what a new house with that lot is worth.

If you have enough credit add on extra loan capacity to finance the value adds.  

I like to keep things stable before I add on more work or financial risk.Definitely raise rents, but would do for the year.

Check with your financing and see what the add ons for non owner occupied are.  

It may sound nice to pay a 5% management fee but the extra fees can add up to be more than the other company that charges 10% with no add-on fees.

The house also had an addon in which the previous owner never pulled permits for (should've researched this more since the addon was not done correctly), and we wanted to ensure that ceiling height were consistent throughout. 

I am thinking should we use some of the equity we have to fund the add on and refinance after paying for another appraisal and the value of the house increasing? 

It may sound nice to pay a 5% management fee but the extra fees can add up to be more than the other company that charges 10% with no add-on fees.

Or should I offer the more personal farm interactions separately as add-ons?

Mark S. add on to what Curt wrote - be mindful that tax assessor has been reassessing property value so what you will pay next year may be different from your current estimate.