Along these lines, any thoughts on fractional ownership?

Concrete requires much less maintenance all the way around. 2) Why are only a fraction of the residential units rented?

It also sounds like you are talking about condominiums/fractional ownership.  

Then put the right number over the left number in a fraction and you have an impact / cost factor.

the bidding starts with an amount that does not tie to any mortgage balance or fraction there ofthe auction is the judicial sales ..plaintiff (bank) is the winning bidder most of the time. sometimes 3rd party bidder wins. this is IL specific.

It's called a fractionalized or multi-lender loan.  

We build 12k housing units a year here up until the crash but its coming back...  4 to 5 thousand are multi family the rest SFRs I would venture to guess there is a fraction of that kind of activity in new construction for multi in Memphis but I could be wrong....  

Even with a hard money lender funding a significant fraction of the deal you still need cash of your own.If you have experience doing the work and have a track record you mind find a money partner who would fund the deal while you do (or get done) all the work.

Yes, the amortizations must be coordinated together, you won't have 120 pay periods, you would have something like 122.7 payment periods and the odd fractional payment owing at the end, if less than the amortized payment would be due with the last payment and not considered a balloon payment, but a final payment.Amateur finance types (uninformed) will not understand the weighted approach to multiple of interest bearing on different loan amounts over different amortized periods, unless they suffered through some statistics or finance classes in college.

Another option that I forgot to mention is to invest in a fractionalized note.