Do you have a partner or kids to consider?

D- Portion the cash in the IRA with other owners cash or partner with someone and apportion it back to the IRA when the deal is complete. 

I know this post is a little old and not sure if you went through with your ADU construction yet, but my partner does ADU ground up construction in the LA area.

I'd really vet the developer, their past projects, talk to prior partners (GP & LP) to see how prior development deals worked out and how the communication was, etc.

Additionally, the boots on the ground partner has to be extremely trustworthy.

I have one bizz partner I sold a 100 unit apartment to 18 years ago for 5 mil and he paid cash..

Our cash on cash return is essentially infinite as we make money on the delta between the yield of the discounted note that we purchase and the interest rate we pay to our passive private capital partners. 

I want a real estate agent with a hustler's mentality, who knows the neighborhoods, studies appreciation and deal analysis already, understands short-term rentals, and is potentially looking to be a scalable partner with me.

Fun example: my business partner had an STR in Sedona with an oddly long laundry room. 

If that is the case is taking on a family member partner.