The first, cheaper, and far more common approach is to attempt to seal the masonry walls to create an isolated space, and then use conventional above-grade building materials to finish the space.

@Brian Garrett,You use business entity structures for many reasons, including asset isolation.

Can I isolate that loss to just me if I had to short sale or forclose without risking my current property i co-own with my wife?

That graph, not spot checking isolated Keywords is really one's SEO effort report card.

Instead of spending 3 hours to find 45 properties spend that time isolating the 300 or 3000 in that area that meet your criteria and send them a letter.

Pretty hard when you are isolated and need to take the boat to get anywhere.Is this an island on a lake or salt water?

Is it a shared cloud or is your data isolated?

Sometimes the units are isolated, sometimes not.

This maybe isolated to my area and I will buy a SFH (Non-HOA) or Multi-Family unit if I can make the same profit I've made from rehabbing and selling the last two condo's.

That way if you sell its as simple as rewiring switch back to isolated control.