You can write a lease for a year, or month -to-month or any other duration you both want.

One thing to note @Richard Covarrubias is that tenants typically stay in duplexes for shorter durations than they would a SFH.

The vacancy goes up, but the LTL comes down because while vacant for the duration of the renovation, the unit is now in the RR at market, just vacant.Every PM and sponsor handles this differently.

They also made a version which has two switches .... one to control the fan with the integrated timer and humidistat and a second for the lights.This spring, they launched new versions of these two switches which now allow you to set the timer duration and the relative humidity at which the fan would be activated.The DewStop switch is the most convenient to retrofit to an existing bathroom or laundry room.  

If I understand right, I make a contract with the owner that gives me ownership of the house but obligates me to make payments for the loan outstanding- but the loan stays in their name for the duration, right?

We agree to lease for the duration of her parents life, in case they are able to be on their own again

Do I need to have a new lease drafted up, or a lease addendum stating we are new landlords, or can I piggy-back off of the previous lease for the duration of his tenancy?

As per Andy Sirkin: "If the buyout involves two or more tenants, none of whom satisfy the "protected" criteria described in the preceding sentence, then the normal owner-occupancy duration requirement under all conversion programs is extended to 10 years.

@Edgar De La TorreThe SLS projects that I have come across were all 12-18 months duration, although it may take longer for the developer to stabilize the property and refinance/sell it.

The position is held in a TIC structure so the investor receives a grant deed for the position and remains independent in the deal for the duration with the ability to 1031 upon exit independent of other investors in the deal.To answer your last question, yes, we are currently performing to the above returns to our investors in the Bay Area buying 20 to 70 unit buildings on the peninsula, specifically San Mateo county.