It could work out nicely or it might not, you'll need to decide what you want to take a risk on.

Any issues you encounter in the beginning time will work out for you.

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.

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. 

Only way I think you could get the info would be to see if you can forecast the work needed to be done based on the inspection and work out the total cost to the HOA.