I like what they are trying to build more than anything else that is under $100/mo and since I only self-manage 3-5 units, it shouldn't be too painful if it doesn't work out.

Work out some sort of split that is fair for what each will contribute and jump in!  

Why dont you and I work out the details, and work on holding one within the next month or two.  

But if that doesn't work out, we're okay with just living in the duplex down unit and renting out unit 2. 

While the lender might need you to also have a partner with experience on the loan that could be your builder and you work out an equity split.

I've even made an offer on a distressed property in my last trip and had a great experience negotiating and trying to workout a deal.

However, this is pretty much doing a BRRRR now which I've never done, don't have the time and is capital intensive (plus, I'm out of town) which doesn't seem too appealing.While I could just weather out the cashflow and bank on the appreciation over time, I feel my return on equity is poor, and that equity can be put elsewhere to be more productive.

Condo conversions are bureaucratically intensive and usually not worth it for 4-Plexes. 

I'm currently working with a realtor right now but will let you know if it doesn't work out.

With all this information you get a total out of pocket estimate, net cash flow and total ROI, which takes into account estimated vacancy (~10%) and property management (15%) and a maintenance/repairs budget.They have target cash flow and ROI percentages for every market they are in, and if the numbers don't work out, that deal never makes to the investor.