The best place to start would be with your IRA custodian.A checkbook IRA would eliminate this issue, and is generally a more effective and efficient tool for IRA investments into rental property. 

I would think you could do it for that and eliminate the whole hassle of shipping it in here? 

Could eliminate the self employment tax on the flip. 

Truly self-directed Solo 401k plan also comes with checkbook control and need for a custodian is eliminated.

A licensed surveyor can probably give you an estimate of eliminating the flooding problem, or tell you if it is possible at all.  

Further, sheltering income via a retirement account does not eliminate the tax, it defers the tax until the income is recognized as a distribution from the retirement account (mandatory distributions begin at age 701/2.).  

Now if you build from the ground up or do a value add lease up with vacancy you can get a higher cap rate.The ones that are already stable in great area the owners will  not let go at a really high cap they will just keep the cash flow then eliminate their equity gain from buying 4 years ago.

In institutional real estate deals, financing contingencies almost immediately eliminate the bidder.

Other renovations included new roof, appliances, AC, flooring, lighting, paint, conversion of 100 amp glass fuse panel to 200 amp thermal CBs and the elimination of gas lines. 

Crazily the government here put out a document that said that they wanted to eliminate gas heat from new construction on the grounds that it is a fossil fuel.