Exactly what @Rich O'Neill said before- there are uglier parts, and a wide array of ARV's.

There are test kits you can buy but like I said investors go in with eyes wide open. 

I could see this being widely abused if not.

I'm looking at buying a property that has a house on a foundation and a double wide that is not on a foundation.

Not usually because they have wide market exposure if it was a good deal someone would have already bought it

@Matthew J.Probably because the sites you are looking are nation wide and they require a selection as a category.I would however like to know how local builders perform this due-diligence process - I have to believe they are checking something somewhere before buying a lot.

@Nick Monge - your description could put you in a wide range of neighborhoods. 

Worked in architecture for 18+ years on a broad array of project types: from large-scale university science buildings, museums and hotels, down to small house renovations.

The driveway is wide and long enough for several cars.

There are two ways to go about marketing/advertising your business...You can go a mile wide and an inch deep, which would be marketing large scale such as blanketing an entire neighborhood with direct mail, door hangers, etc.