Among many, particularly if you're using debt for your project, you'll want a phase 1 environmental report, a geotechnical report to ensure the soils are stable, possibly wetlands report and endangered species if you really want to get into it, an ALTA survey and an extensive title search.

Over the years, I was able to weather both the financial crisis and Hurricane Sandy while keeping my rental and generating monthly cash flow.

Typically when you clean a carpet you are cleaning the surface of the fiber, and if the carpet is maintained properly this is sufficient, How ever a abused carpet will have soils, oils, urine ect. absorbed into the fiber, into the backing, into the padding and even into the subfloor. 

I imagine with a soil survey and a properly engineered foundation it should be possible to build.

However, we definitely like a complete set of plans so we know what we're dealing with in order to provide an accurate bid.Digging out a foundation for beams and footing differ greatly across soil types and foundation types, also being the most expensive part of the build, must be as accurate as possible to bid you a good price without change orders, or going back on the original price.

I would consider long term plans with the house, how prone your area is to soil movement, etc...

The clay pipe had broke and the water had eroded so much soil in the crawl it looked like the Grand Canyon!

(Buckhead and Sandy Springs, for the record.)

From what I've seen, the main things to look for when searching for land is if the land can have septic (perc test) and if the land is suitable for agriculture (soil tests). 

If you had a gas explosion you could have a situation where you may need soil remediation; this can be very expensive and absolutely destroy the value of a lot.