This is the 964th most frequent Norwegian word.
ny
"Ny" means "new" in English.
The word 'ny' is used here as an adjective describing the book, indicating that it is newly acquired or recently published.
Jeg kjøpte en ny bok i går.
I bought a new book yesterday.
The word 'nytt' is the neuter form of 'ny', used as an adjective to describe 'prosjekt' (a neuter noun), signifying that the project has not been undertaken before.
Vi skal starte et nytt prosjekt neste måned.
We will start a new project next month.
Here, 'nytt' again is the neuter adjective form matching 'hus' (a neuter noun), implying the house is recent for them or newly built.