This is the 340th most frequent Polish word.
budowy
The Polish word "budowy" means "construction" or "building" (genitive or plural form).
In this sentence, 'budowy' is in the singular genitive case, used to describe the process or act of building something.
Zasady budowy tego projektu są złożone.
The principles of the construction of this project are complex.
In this context, 'budowy' is in the singular genitive case as part of the idiomatic expression 'w trakcie budowy,' meaning 'under construction.'
Ten most jest w trakcie budowy.
This bridge is under construction.
Here, 'budowy' is used as a plural noun meaning 'constructions'.