If you purchase the property outright with IRA funds, rehab it with IRA funds and then sell it at a profit, ALL proceeds from the sale flow back to the IRA.  

Account Closed Nice to see a post here that doesn't bash Detroit.

Should I proceed?

If you can't figure out whether to proceed by then, you don't need to be buying the house.  

Still somewhat of a newbie so my next question would be should I get the structural engineer first or is it possible to get an estimate from the contractor for just this portion of the project before proceeding.

In less than a decade I will sell my liability (personal residence) and buy an apartment complex with tax free proceeds.

When you do that, he'll be able to help you construct a plan that will achieve your short-term goals that will result in proceeds and resources that will help you pursue and achieve your long-term goals - it's all one master plan.

Achieve your short-term goals that will produce proceeds and resources that will, 2.

Achieve your short-term goals that will produce proceeds and resources that will, 2.

Proceed with caution.