Why mix metaphors with shorashim and binyanim?

QUESTION: Each word has a shoresh. We conjugate those shoreshim and create binyanim (banyan kal, banyan niphal, etc).

But shoreshim don’t create buildings – they produce plants, trees, etc. Buildings have foundation (yesodot).

So why the mix of metaphors? Are the binyanim related to something besides the shoreshim? Are there ‘trees’ or ‘plants’ or something else in Hebrew grammar which grows out of the shoreshim?

Any ideas?

Be well,

Moshe