This is my understanding of the concepts, though it is quite complex so any insight on this strategy would be very valuable.

If so they apply for apartment complexes 5units and up.   

My wife owns a rental property that we plan on selling in the near future, ie coming months.It is a complex situation, but I am having a hard time coming up with the cost basis of the property, estimating the depreciation, which will ultimately give me an idea of the tax bill due at conclusion of the sale.first, the property was purchased (~1988) with what sounds like a lease purchase agreement by her parents (close family member bought the house, parents made lease payments over time with eventual outright purchase of the home from close family member). in 2008, they move into new home but keep as rental. shortly thereafter, second mortgage made on home to cover costs due to family business that eventually went under.

Big difference between SFR, MF, commercial, short term rentals, etc. the most common mistake is to assume that a company managing 400 SFRs is capable of managing a 40 units apartment complex or the other way around.

I've dismissed 1031X recently, thinking it was just too complex and expensive to warrant but I want to be clear on all options. 

Save your kids/wife the pain of probate court. 

Would that be enough to say in court that they can't withhold for those issues.

I have discovered that not many lenders will lend on apartments under 500 square feet, and 3 of the apartments in this complex are under 500 square feet.

@Jeff He for example closing costs are one of the factor and the amount of paperwork we have to do with diff lender in diff state, if I can do the same on a fourplex in a single parcel or focus on a 10 unit complex - i think that would concur only one time i guess.

I am building an 18 unit apartment complex late spring to be completed in 2023.