The type of building material used is a sign of status in housing around the world?

How many gold houses have you seen ?

You just need to apply a little thought..

The answer is 42... or Forty Two, One of those two usually works.

How are 3rd world houses constructed? Brick, stone? Wattle and daub?

Cow poop and real straw in some places... if you were wealthy enough to have at least one cow.