in the works

I am now one of the busiest golf course developers in the United States, with two award-winning, internationally acclaimed course fully operational and two more in the works.


This is from a book by Donald J. Trump. I simply wonder what '(two more) in the works' means?

Does it mean they are under construction?

Not necessarily. It could also mean he is planning them or preparing to construct them.

Then, why did he use 'the works'? It sounds that the meaning shouldn't be vague because of 'the', and what does 'works' imply?

"In the works" is a fixed expression. You can't dissect it.