The bulk of it was in the plastics industry which is when I started REI in 2006.

Those self tapping valves , and the plastic water line are floods waiting to happen ..

I mean, how hard is it to put down a piece of plastic?

They now always have a white plastic film on the roof to protect it from the new car above it from leaking fluids.

The exterior walls are brick with yellow insulation and covered in plastic moisture barrier.

Then, along came Wilsonart and suddenly the atomic ranch exploded into a whole sea of new building materials... formica, plastics, Congoleum, Vinyl, and so on.

She literally tore out the old plastic fridge feed.

For example: there can be no plastic pipe in plumbing, the walls between units must meet certain specifics to be a firewall, if it is forced air each unit will need its own furnace as units cannot share a return air duct, etc.  

Slightly more valuable properties I prefer to rent for less and save the expensive updates for just before selling because that price range buyer is more sensitive to what is in style...beige granite now dated in favor of grayer quartz whereas low end is thrilled with any solid surface over plastic laminate.

If dirt--you'll need to install vapor barrier (heavy plastic) and gravel over that, then possibly some type of flooring.Is it a stone/rubble foundation?